Fiber optic installation

ABSTRACT

The invention relates to a process for introducing an optical cable, in the form of a microcable or minicable ( 1 ), in solid ground ( 17 ) with the aid of a laying unit ( 23 ). The microcable or minicable ( 1 ) used for this purpose comprises a homogeneous and pressurized-water-tight tube ( 8 ) which has an external diameter of from 2.0 to 10 mm and into which optical waveguides ( 3 ) are introduced.

[0001] The invention relates to a process for introducing an opticalcable, consisting of a tube and optical waveguides introduced therein,into solid ground with the aid of a laying unit.

[0002] DE-A1-41 15 907 discloses a cable-laying plough for laying cablesin the ground, in particular in the ground under water. In this case,the blade of the cable-laying plough has arranged in front of it arotating cutting wheel which, in addition, is made to vibratevertically, with the result that hard objects located in the region ofthe trench which is to be excavated may thus also be broken up thereby.This cable-laying plough excavates relatively wide trenches bydisplacing the soil with the aid of the plough blade. Such machines areused, in particular, in coastal areas and under water usingcorresponding control devices. For laying operations in the ground, thematerial is usually removed over a width of from 60 to 100 cm and acable-laying depth of approximately 70 cm, with the result that theoutlay for the laying operation is relatively high.

[0003] Furthermore, DE-A1-30 01 226 discloses a line network fortransmitting signals, the signals being passed through fibre-opticcables which are laid in a network of pipes or ducts of an existingsupply system. In this case, however, fixed cable-laying routes arepredetermined, and inlets and outlets for the cable which is to be laidhave to be provided in a suitable manner therein.

[0004] Alternatively to this, use may also be made, over shortdistances, of so-called drilling or jetting processes in which a tube isintroduced horizontally into the ground. The high outlay for layingmachines and material is also disadvantageous here.

[0005] JP-A-61 107 306 discloses an optical waveguide which is providedwith a metal tube in order to increase tensile strength. The opticalwaveguide is provided with a sheath of vinyl, nylon or urethane, thesematerials having elastic properties and thus protecting the opticalwaveguide mechanically against external influences. In order to increasethe tensile strength, a metallic tube is also applied, loosely at first.Then the tubes are stretched and thus secured to the sheathed opticalwaveguide.

[0006] FR-A-2 677 137 discloses a repair method for optical cables whichare composed of a tube and optical waveguides running therein. At thedefective point, an adapted tubular element is inserted, to which theends of the defective tube are connected again, the defective pointbeing bypassed.

[0007] EP-A-0 553 1991-A discloses a repair method for conventionaloptical cables, two cable sleeves being used in which the connectionsare made between the optical waveguides by means of an intermediatecable element.

[0008] The object of the present invention is to provide a process forintroducing an optical cable in which the outlay for the layingoperation can be reduced, it also being intended that the outlay for theoptical cable system used be coordinated with the laying method. The setobject is achieved according to the invention, by a first process of thetype explained in the introduction, in that the optical cable used is amicrocable or minicable having an external diameter of the tube of 2.0to 10 mm, preferably 3.5 to 5.5 mm, the tube being homogeneous andpressurized-water-tight,

[0009] a laying channel with a width of 4.5 to 12 mm, preferably 7 mm,which is adapted to the diameter of the microcable or minicable, beingintroduced with the laying unit into the solid underlying layingsurface,

[0010] the microcable or micro[sic]cable being introduced into thelaying channel by means of a feed element and being held at a constantlaying depth, the laying channel being filled with filling materialusing a filling device which is moved along after the insertion of themicrocable or minicable.

[0011] The object which has been set is thus achieved in accordance withthe invention planning to a second method of the type mentioned at thebeginning in such a way that a microcable or minicable with an externaldiameter of the tube of 2.0 to 10 mm, preferably 3.5 to 5.5 mm ispressed into utility lines for sewerage, gas or water, which have beenleft open, using a laying unit.

[0012] The object which has been set is achieved according to theinvention using a third method of the type mentioned at the beginning inthat the optical cable used is a microcable or minicable with a diameterof the tube of 2.0 to 10 mm, preferably 3.5 to 5.5 mm, which is insertedinto existing, active utility lines for sewerage gas or water using alaying unit.

[0013] A great advantage of the process according to the invention isthat only a relatively short amount of time is taken for the layingoperation, with the result that it is used particularly whereverlong-term hold-ups are undesirable. This is the case, for exampleparticularly when laying new or additional cables, when the layingoperation has to be carried out in urban areas with heavy traffic.Blocking off or diverting is to be avoided as far as possible. Theoperations of cutting, laying and sealing the channel can take placedirectly one after the other, these operations expediently being carriedout all in one go by a multipurpose machine. In this manner, the trafficdisruption is barely greater than that caused by a road sweeper. Thereis also such a need, for example, when all the laid pipes, cable ductsor pipelines have already had cables laid in them, it then beingpossible to splice onto the newly laid cables without interruption.Tubular mini communication cables, which are referred to as microcablesor minicables, are particularly suitable for this purpose. These newlylaid minicables or microcables may preferably be connected to form aredundant overlay network.

[0014] According to the invention, such a minicable or microcablecomprises a homogeneous and pressurized-water-tight tube of very smalldiameter of from 2.0 to 10 mm, preferably 2.2 to 5.5 mm. These tubeshave a wall thickness of from 0.2 to 0.4 mm. The most favourable valuesas regards the buckling resistance are achieved with a wall thickness toan external diameter ratio of between ⅕ and {fraction (1/20)},preferably approximately {fraction (1/10)}. The smallest internaldiameter of the tube used is 1.8 mm. This tube may be produced frommetal, for example from chromium-nickel-molybdenum (CrNiMo188) steel,aluminium alloys, copper or copper alloys or from plastic, for examplewith reinforcement inserts consisting of carbon fibres, glass fibres, ora sintered carbon-fibre structure. These tubes may be extruded, welded,folded or bonded longitudinally at the overlap. The optical waveguidesare then introduced into the tube either after the empty tube has beenlaid or at the factory. The optical waveguides can be blown in or jettedin.

[0015] The tubular minicable can be introduced into solid ground byvarious types of process according to the invention:

[0016] 1. The laying may be carried out by means of a laying machinewhich has a cutting wheel, with the aid of which a narrow laying channelhaving a width of from 4 to 12 mm, preferably 7 mm, and a depth of from50 to 100 mm, preferably 70 mm, is cut in the ground, in particular inan existing roadway.

[0017] 2 Such a minicable may also be forced into disused supply lines(wastewater, gas, water). Disused pipelines of utility companies areparticularly suitable for a laying operation. They correspond largelywith the supply network planning to be set up. Even if the disused pipesare in bad condition, it is possible to introduce the thin metal tubesof the minicable since they are pressed in in the longitudinal directionand pass through obstructions such as dirt, rust and the like. Theminicable does not buckle in pipes since it is supported by the disusedsupply line. After leaving these pipelines, the laying operation mayalso be continued with the aid of other laying processes.

[0018] 3. It is likewise possible for a minicable to be pushed intoexisting, active supply lines (wastewater, water). The function of thesupply lines is barely impaired to any extent at all in this case. Thetubular minicable is resistant to pressurized water, wastewater andcorrosion. Gnawing by rodents can be ruled out due to the large wallthickness of the metal tube. It can be assumed that theoptical-waveguide network which is to be installed corresponds with theexisting supply network. Earthworks may thus be reduced to a minimum.Appropriate fittings which make it possible to lift the minicable out ofthe supply lines are to be provided at the appropriate locations.

[0019] 4. Minicables may likewise be introduced into the ground byearth-displacement or jetting processes. In this case, first of all thetube of the minicable is introduced, as a mechanical protection, intothe ground. Expediently, the fibre conductors, or very thin blownfibres, are subsequently blown or jetted in. In order to minimize thefriction during the blowing-in operation, the tubes, which are producedwithout seams and are smooth on the inside, are coated with a plasticlayer, e.g. PTFE. This layer is, for example, deposited from a PTFEsuspension when the metal tube is heated correspondingly. Moreover, thislayer protects against corrosion and soiling of the tube interior.Earth-displacement and pressing-in operations in which a drilling headwith a bevel rotates constantly are known. If the drilling head does notrotate, the drilling body is deflected in accordance with the bevel. Itis thus possible to bypass obstructions. A water jet at very highpressure may, for example, force away small stones. The tube cuts orjets its way through the ground and assists the advancement of thepressing-in process. Moreover, the water pressure can move a piston inthe drilling body. The thrust-like movement of the drilling head thenbreaks through obstructions more easily and reduces the static frictionduring the drawing-in operation.

[0020] By elastic expansion of the tube, the wall friction with respectto the earth can be reduced further. For this purpose, an outlet valvewould have to be provided at the end of the tube.

[0021] Using the tubular minicable according to the invention, then,results in particular advantages, as follows. The laying or introductiontakes place with the aid of a hollow tube, which, as cable, is alreadyprovided with optical waveguides; however, it is also possible for theoptical waveguides to be drawn in subsequently. Appropriate selection ofthe wall thickness ensures sufficient protection against mechanicalloading, corrosion and gnawing by rodents. Moreover, the tube has a highstability to transverse compressive stress. For lengthening and thinningthe tube, use may be made of methods, which are known per se, withcutting clamping rings or a crimping process. For lengthening a tubeconsisting of copper, connection by cold pressure welding is possible,for example. Otherwise, the tube can be processed like a normalinstallation pipe, these methods relating to bending, provision offittings, branchings and inlets in sleeves. Also suitable for thispurpose are cylindrical metal fittings into which the minicable can beintroduced tightly. When the laying operation is taking place from thesurface of the ground, the surface is only minimally broken up, which isparticularly advantageous for laying operations in roads. Moreover, as aresult of the rigidity, pulling and pushing the minicable is possibleand helpful in the laying operation. Due to the small diameter of such aminicable, the earth displacement is also particularly low, it beingpossible for the earth to be displaced when the cable is pressed ordrawn into the surrounding earth.

[0022] A tubular microcable or minicable is particularly suitable forlaying in a roadway or in footpaths since the roadway formation isbarely broken up by the necessary channel. All that is necessary inorder to ensure the safety of such a cable is a channel having a widthof 4 to 12 mm and a depth of approximately 70 mm. In this case, thechannels for receiving the cables should, as far as possible, only beprovided on the sides of the road since stressing is at its lowest here.The channel which has been introduced is refilled after the introductionof the cable or of the tube and is sealed against the penetration ofsurface water. This sealing must not produce any cavities in whichsurface water can collect. The roadway surface can be restored in asimple manner. All that is required during repair work is that, when theroad surface is cut away, the minicable or microcable which has alreadybeen laid is not damaged.

[0023] A laying operation using a microcable and the correspondinglaying process according to the invention produces considerablereductions in the costs for the laying method, this resulting in aconsiderable reduction in the overall line-laying costs in the case of anew installation. Moreover, the operational reliability is increased byredundant routing.

[0024] It is also advantageous that annular network structures withvarious connection possibilities can be formed from former rigid,star-shaped branching networks. A flexible, intelligent network designis obtained in this manner, it being possible for microcables to beswitched in with the aid of optical switches. A pigtail ring withoptical switching, in which optical fibres could be routed as far as thesubscriber, would thus be possible. It is highly advantageous thatsubsequent laying operations in roads, footpaths, cycle paths,curbstones and the like are possible with a low degree of outlay.Consequently, a technical concept may be adapted in a simple manner tothe wishes of the operator, it being possible to utilize the existinginfrastructure (wayleaves, and pipes for wastewater, gas, district heat,etc.) It should also be noted here that, in comparison with the standardmethod, this method can save a large amount of time.

[0025] Various points should be noted when a laying channel is providedin an asphalt surface of a federal road which is made up of a topsurface course of 4 cm, a binder course of approximately 8 cm and a basecourse of from 10 to 15 cm. The proportion of bitumen decreases towardsthe base course, but the coarse-grained fillers increase. However, thebitumen ensures the cohesion within the individual layers. Duringcutting as far as the asphalt base course, the laying channel is, then,dimensionally stable, with the result that no material caves in and theoverall upper road structure remains intact. During cutting, it is notpermitted to cut through the bitumen base course as far as theanti-frost layer of the substructure since this may result in weakpoints in the series of asphalt layers, which weak points could break upthe layer formation and result in damage to the road within a shortperiod of time. However, if the minicable is laid in a water-tight andfrost-resistant manner, the soil mechanics are not influenced by thisintervention. However, modern roads are frost-resistant since thecrushed-stone substructure bears and absorbs loads. This dischargesgravitational water into the earth or into drain pipes, and a sealed,intact surface course does not let in any surface water. Frost damagecannot therefore occur. This minimum laying-channel width andvibration-free cutting means that the mechanical structure of the roadremains intact. Directly after the laying operation, the laying channelis closed off again in a frost-resistant manner by a hot-melting bitumenor by a fusible preformed bitumen filler.

[0026] However, very heavy traffic may result in additionalconsolidation and flow in the upper structure of the road (lane grooves,shoulder). It is thus recommended that the laying channel is foam-filledwith a curable plastic around the minicable directly after the latterhas been laid. After curing, the foam filling achieves a compressivestressability which is sufficient for further distributing the load ofthe carriageway surface uniformly. Cavities and interstices between theminicable and the laying channel are filled, without leaving anycavities which could receive any surface water which may penetrate andpropagate this surface water along the minicable.

[0027] Vibrations due to the heavy traffic are absorbed by the foamfilling and are not passed on to the minicable. Relatively smalloccurrences of the earth subsiding may also be compensated for by theelastic foam, with the result that such irregularities in the bitumenbase course would not result in the failure of the minicable due tobending of the tube or fibre elongation.

[0028] For a minicable according to the invention, compressed-gasmonitoring and monitoring with a liquid, for example, are also possible.The minicable may thus also be filled with a liquid which, in the caseof the tube having a defect, escapes and resinifies under the action ofair. This ensures a kind of “self-healing”.

[0029] Moreover, the minicable is interception-proof since the opticalwaveguides cannot be bent. The minicable is stable with respect totransverse forces, has a high tensile force, is compact and, on accountof the small diameter, has a relatively low weight and little friction.The tube, which acts as the cable sheath, also assumes, at the sametime, the tensile-force function of the otherwise customary centralelement. In this high-strength cable with very low expansion, there isno problem in respect of excess lengths when the minicable is drawn inand laid. This configuration gives a higher strength in comparison witha normal cable with a conventional plastic cable sheath, with the resultthat it is also possible to work with considerably larger drawing-inforces. Moreover, straightforward earthing is possible in the case ofthe metal embodiment. If use is made of a plurality of tubes which areinsulated with respect to one another, the metal cross-section may alsobe used for supplying power to active components. By using metal tubes,it would also be possible for overhead cables to be of a considerablymore straightforward construction. A supporting element (e.g. amessenger wire) could then be dispensed with since the metal tubesassume this function. In addition, such a minicable ispressurized-water-tight, gas-tight, forms a water vapour barrier andgives protection against the gnawing of rodents. Furthermore, it isfire-resistant, has excellent heat-dissipation properties and isresistant to aging and corrosion.

[0030] The flexibility of the minicable or of the tube can be improvedby a grooved sheath.

[0031] Further developments of the invention are given in subclaims.

[0032] The invention will now be explained in more detail with referenceto 57 figures.

[0033]FIG. 1 shows a construction of the tubular microcable or minicablewith a capping.

[0034]FIG. 2 shows, schematically, a longitudinal section through theminitube without optical waveguides.

[0035]FIG. 3 shows, schematically, the laying operation for a minicable.

[0036]FIG. 4 shows the forcing-in process for a minicable.

[0037]FIG. 5 shows the pushing-in process for a minicable.

[0038]FIG. 6 shows the jetting process for a minitube.

[0039]FIG. 7 shows the method of laying the tubular minicable with thelaying channel already filled again.

[0040]FIG. 8 illustrates the cross-section of a roadsurface with alaying channel cut therein.

[0041]FIG. 9 shows the laying channel which has already been filled in.

[0042]FIG. 10 shows a U-shaped holding-down device for microcables inthe laying channel.

[0043]FIG. 11 shows a rivet-like metal bolt as holding-down device forminicables.

[0044]FIG. 12 shows a plan view of the sketched construction of abending device for thin-walled tubular microcables or minicables.

[0045]FIG. 13 shows the laying channel filled with hot bitumen andcoloured glass particles.

[0046]FIG. 14 shows a length-equalizing loop in a longitudinal sectionthrough the road surface along a cut laying channel.

[0047]FIG. 15 shows a sleeve for a tubular microcable or minicable.

[0048]FIG. 16 shows a laying channel for laying a minicable ormicrocable.

[0049]FIG. 17 shows a widened laying channel before the resultingcentral web has been broken out.

[0050]FIG. 18 shows the cross-section through the cutting-wheelarrangement of the laying unit.

[0051]FIG. 19 shows a spacer ring with rectangular grooves on its outercircumference.

[0052]FIG. 20 shows a spacer ring with sawtooth-shaped grooves on itsouter circumference.

[0053]FIG. 21 shows the arrangement of brushes on the outercircumference of the spacer ring.

[0054]FIG. 22 shows the lateral offset of hard-metal teeth.

[0055]FIG. 23 shows a laid microcable with a tension-resistant releaseelement laid in addition.

[0056]FIG. 24 shows a laid microcable with a filling profile as fillingmeans for the laying channel.

[0057]FIG. 25 shows the electric connection of two minicables ormicrocables via a metallic cable sleeve.

[0058]FIG. 26 shows an insulated microcable with an insulated powercable.

[0059]FIG. 27 shows a non-insulated microcable with an insulated powercable.

[0060]FIG. 28 shows a non-insulated power cable with an insulatedmicrocable.

[0061]FIG. 29 shows an insulated microcable with a cable holding-downdevice.

[0062]FIG. 30 shows a microcable with an additional cable in a commoninsulation.

[0063]FIG. 31 shows an embodiment according to FIG. 30, but with a webconsisting of insulation material located in between.

[0064]FIG. 32 shows two electrically insulated minicables ormicrocables.

[0065]FIG. 33 shows two minicables or microcables within a commoninsulation.

[0066]FIG. 34 shows a sketch of the process being carried out.

[0067]FIG. 35 shows the laying of the minicable or microcable withmagnet-containing cable holding-down devices.

[0068]FIG. 36 shows U-shaped, magnetic cable holding-down devices in thelaying channel.

[0069]FIG. 37 shows bar-like, magnetic cable holding-down devices in thelaying channel.

[0070]FIG. 38 shows bar-like cable holding-down devices which are linedup in a row on support filaments.

[0071]FIG. 39 shows a cable holding-down device which has its endsclamped on support filaments.

[0072]FIG. 40 shows a cable holding-down device which is fitted into asupport sheet.

[0073]FIG. 41 shows the laying of the microcable with electronic signalgenerators as holding-down devices.

[0074]FIG. 42 shows a chip which can be freely programmed from theoutside, is fitted along the microcable and is lined up on supportfilaments.

[0075]FIG. 43 shows a programmable chip which is accommodated in asleeve.

[0076]FIG. 44 shows a defective microcable.

[0077]FIG. 45 shows a plan view of the repair location.

[0078]FIG. 46 shows a cross-section of the repair location.

[0079]FIG. 47 shows a unit for exposing the laying channel.

[0080]FIG. 48 shows a foam-rubber element introduced in the longitudinaldirection.

[0081]FIG. 49 shows a laying channel with a profile body of circularcross-section before the compression operation.

[0082]FIG. 50 shows the laying channel after it has been closed off.

[0083]FIG. 51 shows a laying unit.

[0084]FIG. 52 shows a longitudinally slit, annular profile body which isfitted on the microcable.

[0085]FIG. 53 shows the arrangement according to FIG. 52 after thelaying channel has been filled.

[0086]FIG. 54 shows a profile body with longitudinally running freeducts.

[0087]FIG. 55 shows the profile body according to FIG. 54 in the layingchannel.

[0088]FIG. 56 shows a profile body which is coated with a sealant.

[0089]FIG. 57 shows an exemplary embodiment for heating the sealantduring the laying operation.

[0090]FIG. 58 shows the covering profile after the laying operation inthe laying channel.

[0091]FIG. 59 shows a cross-section of the mechanical influence of thepointed object.

[0092]FIG. 60 shows a front view of the influence of the object on thecovering profile.

[0093]FIG. 1 shows the construction of a tubular microcable or minicable1, the cable end 2 being provided with a drawing-in or drilling tip 5.The arrow 6 indicates the drilling movement or advancement direction ofthe drilling head. Running in the interior of the minicable 1 are theoptical waveguides 3, which may be introduced either at the factory orafter the laying operation. The outer surface of the minicable isprovided with a surface protection 4.

[0094]FIG. 2, then, shows the tube 8 of the minicable 1, in the interiorof which, that is to say in the central duct of which, opticalwaveguides have not as yet been provided. In this case, the said centralduct serves initially as a pressurized jetting duct for the layingoperation. Thus, an appropriate medium, for example a suitable liquid,is injected under pressure, with the result that the earth is jetted outand displaced at the end 11 of the minicable. In addition, rotatingmovement of the drilling tip 10 in accordance with the arrow directions12 can increase the action. Following the laying operation, the opticalwaveguides or so-called blown-fibre conductors are then introduced intothe tube 8 of the minicable 1. On the left-hand side of the minicable,the letter P symbolizes the pressure, required for the jetting process,by which the medium is injected. If a valve is provided at the end ofthe drilling tip 11, corresponding control allows the liquid to bepulsed out under pressure. At the same time, the tube 8 could increaseand decrease in diameter in an oscillating manner, this eliminatingstatic friction with respect to the earth.

[0095]FIG. 3 displays a method of laying a tubular minicable in thesand, gravel, earth or asphalt with the aid of a laying unit 23, bymeans of which a laying channel 19 is cut in the surface 14 of theground 17. Covering slabs or cobble stones are removed beforehand. Themachine comprises a linkage 22 on which the required individual partsare combined to form a unit. All the process steps are coordinated withone another. In the case of the laying channel 19 which is to beprovided in the laying direction 21, a cutting wheel 15 withcorresponding cutting teeth, which cut a thin laying channel 19 withsteep side walls, leads. The width of the laying channel is justsufficient to receive the tubular minicable 1 and the laying blade 18.Said laying blade 18 protects the side walls against caving in, guidesthe minicable 1 along and, via a cable-fixing means 7, holds constantlyat the laying depth that end of the cable which is to be laid, theminicable or microcable 1 being fed from a ring, which is wound up on alaying reel 24, via advancement rollers 25. A jetting rod 16 compactsthe deposited earth or filling sand 20 behind the laying blade 18. Thisoperation takes place directly after the excavating operation. It isthus not possible for the side walls of the laying channel in the region13 of the laying machine to cave in. Surrounding earth will not cave in,with the result that the surface 14 will not sink. The cutting wheel 15,the laying blade 18 and the jetting rod 16 together form the laying unit23 and are connected rigidly to one another via a linkage 22. A drive 30moves the entire laying unit 23 continuously in the laying direction 21.The end 29 of the minicable is introduced at the beginning of the layingchannel 19 via a so-called laying bow 26 and a laying thimble 27. Thecentral connection 28 for pressurized water jetting is provided on thelaying unit 23. Following the laying operation, the road surface isrestored or sealed.

[0096] Such laying operation gives particular advantages since all cabletypes with a small diameter can be laid, the outlay being essentiallylower than for conventional laying with a wide trench. During the layingoperation, the minicable is both drawn by the laying blade and guidedalong by the advancement rollers. Pulling and pushing of the minicableduring the laying operation can reduce the tensile loading. Moreover,the tubular design of the minicable prevents buckling during laying inthe channel. Excavating, laying, filling in and sealing the ground takeplace directly one after the other and constitute a preciselycoordinated operational sequence. The cable is supported by the verynarrow laying channel, with the result that the risk of buckling isreduced. Moreover, in the case of such a narrow laying channel, the soilmechanics and the surface of the ground are only minimally disturbed, sothat post-treatment is not necessary. The coordinated operationalsequence does not allow the side walls of the laying channel tocollapse, so that the soil is also prevented from caving in afterwards.If the blown-fibre method is used for introducing the opticalwaveguides, one or more hollow tubes are laid, as a result of whichpressurized water may then be channelled directly onto the cuttingwheel. This loosens the rocks or the subsoil.

[0097]FIG. 4 illustrates the system for the forcing-in process, by meansof which a minicable 1 is forced into a disused supply line 31. It isindicated that the minicable 1 which is to be forced in may, forexample, also come up against accumulation of dirt 32 which constitutesblockage of the supply line. Corresponding pressure has to be used topass through this accumulation of dirt 32. This figure furtherillustrates that the disused supply line 31 may have a plurality ofbranchings, so that it would also be possible for minicables to beintroduced from there. Valve openings 33 which are originally used forthe supply line and are each provided with a covering could be utilizedfor sleeve inserts for the newly introduced minicable system. At thestart of the injection location, the minicable 1 is likewise introducedvia a so-called laying bow 26 and a laying thimble 27, advancement beingeffected, for example, once again by means of advancement rollers 25.Here too, the minicable 1 is drawn off from a laying reel 24. It is alsopossible here for pressurized water to be injected, via a centralconnection 28 for pressurized water, to the end location of theintroduced minicable 1.

[0098]FIG. 5 illustrates the introduction of a minicable 1 into anexisting supply line, for example into a water pipe. At a bend 36 of thesupply line 35, the minicable 1 is introduced via an outlet location 37,the inlet location being provided with a corresponding seal 38. Theminicable 1 is advanced within the supply line with relative ease sincethere are no expected obstructions. Gas or flowing water injected intothe supply line assist the advancement of the minicable.

[0099]FIG. 6 illustrates the jetting process for a minitube, which isthen provided with optical waveguides in the second process step by theblown-fibre principle and thus forms the finished minicable. As hasalready been indicated, first of all only the empty minitube is jettedinto the earth 17. In this case, pressurized water is channelled intothe minitube via the central connection 28, this resulting in theformation, at the end of the drilling head 40, of a pressurized jettingcone 39 by means of which the earth 17 is jetted out. The drilling tip40 is, in addition, made to rotate 41 in order to increase thejetting-out action. The minitube is also expediently made to rotate 42at the inlet location. After the minitube has been laid, the opticalwaveguides are then jetted or blown in by the blown-fibre process. Theinner wall of the tube is coated with plastic in order to improve thesliding movement of the fibre element during the blowing-in operation.

[0100]FIG. 7 illustrates the laying of a microcable in an asphalted roadsurface. As a supplement to laying the minicable 1 in a cut layingchannel 19, the laying channel 19 is first of all partially filled witha curable filling foam 43 after the minicable 1 has been laid. Finally,above this filling foam, the laying channel 19 is filled with awater-tight closure 44, for example consisting of hot bitumen, with theresult that the roadway surface is sealed off again. It can further beseen from FIG. 7 that a road structure is made up of various layers. Ananti-frost layer 48, generally comprising crushed stones, has a basecourse 47 arranged on it. The latter is adjoined to the top by a bindercourse 46, which, finally, is sealed by a surface course 45. It can begathered from this that the laying channel 19 must not cut right throughthe base course 47, in order that the supporting function is notimpaired.

[0101]FIG. 8 illustrates the position of the laying channel 19 by a roadcross-section with the above-described layer structure comprising ananti-frost layer 48, an asphalt base course 47, a binder course 46 and asurface course 45. It is only the surface course 45 and the bindercourse 46 which are cut through by the laying channel 19, the asphaltbase course 47 only being cut to a partial extent. Depending on thenature of the road surface, the cutting depth is between 4 cm and 15 cm.A laying depth of approximately 7 cm is optimum.

[0102]FIG. 9 illustrates the same structure as in FIG. 8, but it is alsoshown how the laying channel 19 is filled again and closed off after thetubular minicable has been laid. It can thus be seen that the base ofthe channel is provided, around the minicable 1, with a curable fillingfoam, over which a bitumen sealing compound or a preformed bitumen jointfiller is introduced in a sealed manner. It would also be possible forthe filling material 49 to be applied to the microcable, as the cablesheath, at the factory. It would form an additional protection forlaying the microcable. Suitable means or processes e.g. with the supplyof heat, could make the filling means expand. The laying channel 19 isconsequently sealed off, so that it is not possible for any surfacewater to penetrate. Optical waveguides 50 are indicated in the interiorof the minicable 1. In order to rule out damage during laying andcorrosion to the outer sheath of the metallic tube by leakage currentsin the ground, the minicable 1 is provided on the outer side with anon-conductive protective layer 51 which insulates the metal withrespect to the earth. A thin cable sheath of plastic can be applied asthe protective layer. For this purpose, a firmly adhering wear-resistantcoating may also be applied. The channel is sealed off with hot bitumen.If a preformed bitumen joint filler is used to seal the laying channel19, then it is introduced into the laying channel 19 on edge and thesurface courses to be connected are heated with a gas flame or infrareduntil a liquid bitumen film is obtained. A slight excess of thepreformed bitumen filler is subsequently rolled into the joint and thuscloses off the channel in a water-tight manner.

[0103]FIG. 10 illustrates how the laid minicable 1 is fixed by U-shapedholding-down devices 52. These U-shaped clamps 52 are pressed into thecut laying channel 19 from above. In this case, the web 54 of the clamp52 holds down the laid microcable or minicable. Tolerances in thechannel width are compensated for by the spring action of the lateralflanges. The flange ends may be provided with lateral claws 53 so thatthey can engage in the side walls of the laying channel 19. If thefilling compound softens, for example, due to hot temperatures, thecable holding-down devices 52 hold the microcable or minicable inposition without allowing it to rise up.

[0104]FIG. 11 shows a further exemplary embodiment for cableholding-down devices 57. These comprise rivet-like metal bolts which aredriven into the cut laying channel 19 by means of their resilient shank57. The lens-shaped head 55 terminates at the roadway surface or isslightly elevated. The cable route is easy to recognize by the heads 55of the holding-down devices. The shank of the cable holding-down device57 is provided with barbs 56.

[0105]FIG. 12 illustrates a bending device for cable branchings andequalizing loops for thin-walled tubular microcables or minicables. Inthe case of very small wall thicknesses, the microcable or minicable isvery sensitive to buckling. However, radii down to 30 mm can be producedwithout buckling by a bending device 61. For this purpose, themicrocable 1 is fixed with clamping tongues 62 and drawn around abending mandrel 60. For simple manipulation, a pressure-exerting roller59 can draw the microcable or minicable 1 around the bending mandrel,the hand lever 58 being actuated in the arrow direction. The pivot point63 of the hand lever is located in the axis of the bending mandrel 60.

[0106]FIG. 13 illustrates an exemplary embodiment for a marking of themicrocable or minicable route. Such a marking is particularly importantfor locating a microcable or minicable and serves, at the same time, asa warning marking for road construction work. The cut laying channel 19is hermetically sealed with a hot bitumen 65. In this case, the hotbitumen 65 has glass splinters 64, for example, added to it as filler,with the result that, when light shines thereon, the course of thelaying channel 19 is shown up by the reflection of light. Hot bitumenusually has a very low viscosity for processing. For a laying-channelwidth of from 7 to 10 mm, the viscosity of the hot bitumen can beincreased by aggregates. The mechanical properties of the sealingcompound may then also be compared with those of the existing roadsurface. For the marking, use may be made of ground, coloured glasssplinters as fillers and aggregates. Different colouring and reflectionmean that the cable route may then be recognized clearly. Under normalwear of the roadway surface, a number of glass particles are alwaysexposed and are thus easy to recognize.

[0107]FIG. 14 illustrates that the microcable or minicable may beprovided with equalizing loops 66 for length equalization and also forcable lead-throughs at a sleeve. This means that excess lengths aretaken up during laying and crimping of the tubes and that subsidence inthe earth, in the road and expansions in length in the microcable orminicable and the road surface are compensated for without detrimentallongitudinal stressing. Such equalizing loops 66 are to be fitted duringlaying, in which case the laying channel 19 has to be provided at theappropriate locations with a corresponding depression 67 or widening inorder to obtain sufficient space for the equalizing loop 66. Suchequalizing loops 66 are preferably to be fitted in front of sleeves,cable branches and bends. If a microcable or minicable is to be laid atright angles, then a core hole has to be introduced vertically into theupper road structure. In this case, the diameter depends on the minimummicrocable or minicable radius which can be bent without buckling bymeans of the abovedescribed bending device. The core hole shouldsubsequently be sealed again in a frost-resistant manner by asphalt.U-shaped bends of the minicable are also possible instead of theequalizing loops.

[0108]FIG. 15 illustrates an arrangement for a sleeve 68 into whichmicrocables and minicables 1 are fed via cable inlets 70. Theappropriate measures such as connecting or splicing are then carried outin the interior of the cable sleeve. Such a cable sleeve preferablycomprises a round steel cylinder and is introduced into a core hole ofthe ground 17. A sleeve cover 69 which can be placed in position fromabove closes off the sleeve interior. After the sleeve 68 has beenintroduced and the microcable 1 has been introduced in the sleeve, theupright core hole, which can lead into the substructure of the road, isconcreted into the roadway in the lower region. The sleeve is thus nolonger subject to settling. Sealing with respect to the upper roadstructure 72 is effected with asphalt or liquid hot bitumen. Sealing inthe cable inlets 70 takes place, for example, with conventional cuttingring seals or other seals which are known per se for cable sleeves. Thincopper tubes into which the cable ends can be introduced have alsoproved expedient. These are crimped onto the outer wall of themicrocable by radial pressing. These crimped connections are resistantto tension and pressurized water. At the top, the core hole isterminated by a load-bearing cover 73 level with the road surface 72. Ifnecessary, it is also possible for the cover to be located beneath theroadway surface. The optical waveguides may be arranged, in a mannerknown per Be, with excess lengths and splices in the interior of thecable sleeve 68. The round embodiment of the cable sleeve 68 means thatit is expedient to introduce the optical waveguides helically, with theresult that they can easily be moved upwards if required.

[0109] It is also advantageous to use a small shaft instead of thesleeve 68, this small shaft, in turn, receiving a sleeve.

[0110] Discharge means and feed means may likewise be run, as minicablesor microcables, in a manner of an overhead cable or non-supported cable.

[0111] The object of one development of the invention is to find aprocess with the aid of which it is possible to cut laying channels forminicables or microcables in the solid ground in one operation. The setobject is achieved, in accordance with the process explained in theintroduction, in that a laying channel is cut by means of a laying unitwhose cutting-wheel arrangement is varied in terms of thickness suchthat the width of the laying channel is adapted in one cutting operationto the corresponding diameter of the microcable or minicable used.

[0112] Advantages of the process according to the development of theinvention may particularly be seen in that it is now possible to producelaying channels in solid surfaces such as asphalt and concrete, roadsurfaces, curbstones or stone slabs by means of a laying unit in whichthe cutting width can be set to the respective diameter of the minicableor microcable used. For this purpose, for example a cutting-wheelarrangement comprising two standard blades with the interposition of aspacer ring is drawn onto the axle of the laying unit. Exchanging thespacer ring means that the cutting width can thus be changed.

[0113] In the case of wide laying channels, a central web first of allremains in the ground, but the invention provides measures by which theresulting central web is broken out at its base during the cuttingoperation. This is effected by appropriate configuration of thecircumferential surface of the spacer ring, e.g. by introducing groovesof a suitable shape, for example of a rectangular or sawtooth shape, orby providing bar-like, flexible brushes on the circumference. These alsoclean the channel of abrasion dust. This results, in particular, in theadvantages outlined below:

[0114] Production of rectangular laying channels of any width.

[0115] The width of the laying channel can be determined by exchangingthe spacer ring.

[0116] The double cut in one operation means that the wear on tools isuniform, the blades not being subjected to bending stress, so thatunbalances do not occur.

[0117] The initially produced central web in the laying channel isbroken out at the base during the cutting operation.

[0118] Appropriate configuration of the outer circumference of thespacer rings means that the laying channel is also cleaned at the sametime.

[0119]FIG. 16 shows a rectangular laying channel VN in a solid groundsurface SO, a double arrow indicating that the channel width VB has tobe variable in accordance with the minicable or microcable type MK usedin order to be able to achieve the necessary width in a single cuttingoperation.

[0120]FIG. 17 illustrates the production of the widened laying channelby two blades which are spaced apart from one another in accordance withthe respectively introduced spacer ring, with the result that a centralweb MS first of all remains between the two partial channels TN1 andTN2. However, appropriate circumferential configuration of the spacerring means that this central web KS is immediately broken off at thebase BS during the cutting operation, this resulting in the wide layingchannel shown in FIG. 16.

[0121]FIG. 18 illustrates a cross-section of the cutting-wheelarrangement, which comprises two blades TS1 and TS2 with a spacer ringDR located therebetween, the width of the spacer ring DR being selectedsuch that the ring, together with the two blades TS1 and TS2, providesthe necessary width for the laying channel VN. The drive axle AS isintroduced in the laying unit VE via corresponding linkages G.

[0122] FIGS. 19 to 22 illustrate the configuration of the circumferenceof the spacer ring DR, the blade TS2 having been removed for thisillustration. The blade TS1 is provided with appropriate cutting teethin the conventional manner. These cutting teeth Z may also be providedwith hard metal. If appropriate, the cutters may be exchanged.Preferably, the cutters should be made to protrude alternately beyondthe cutting blade TS3 from the blade centre, as can be seen from FIG.22. This screwing action allows the blade TS3 to cut a clearance at thechannel flanks FL. “Seizing” is avoided. The spacer ring DR is providedon its circumference with grooves or cutouts of widely varyingconfiguration which break off the central web and clean the layingchannel. An air pressure by which the laying channel is freed offragments is produced by way of the cutouts or grooves. Thissimultaneously achieves self-cleaning of the laying channel as it isproduced.

[0123]FIG. 19 illustrates rectangular cutouts RA, and FIG. 20illustrates sawtooth-shaped cutouts SA, on the outer circumference ofthe spacer ring DR. In FIG. 21, this operation is carried out with theaid of bar-like, flexible brushes B by way of which the central web isbroken and the fragments are removed from the laying channel VN.

[0124]FIG. 22 illustrates the lateral offset or staggering of thehard-metal teeth Z, which make it possible for a blade TS3 to runfreely. This arrangement applies for each of the blades.

[0125] It is also possible to use such cutouts RA to cut out a materialwhich has the properties of bitumen.

[0126] The object of a further development of the invention is to find aprocess by which the laid minicable or microcable can be removed againfrom the laying channel, in which case the filling material has to beremoved beforehand. The set object is achieved according to theinvention, in accordance with a process of the type mentioned in theintroduction, in that a tension-resistant release element for liftingthe laid minicable or microcable is introduced, when said cable is laidin the laying channel, above the minicable or microcable in the fillingmaterial of the laying channel, in that the tension-resistant releaseelement is then drawn out during the lifting operation, in which casethe laying channel is also released of filling material, and in that theminicable or microcable is then removed from the laying channel.

[0127] The problem with lifting the minicable or microcable (only theterm microcable will be used from now on) is that the cable runs in alaying channel which is covered in a sealed and well-adhering mannerwith a filling material above the microcable. In this case, use is madeof a filling material which has viscous and adhering properties, forexample bitumen. Accordingly, the microcable cannot be drawn out beforenot the filling material is removed. Likewise, further, secondarycutting of the laying channel is not an option since the fillingmaterial would only smear on account of its viscous consistency. Theinvention solves this problem, then, in that a tension-resistant releaseelement is embedded above the microcable, which release element can bedrawn out or pulled out if required and also removes the filling meansin this operation. It is advantageous here if, from the outset, themicrocable is not wetted with the filling means, so that, as far aspossible, there is no adherence between the two. The tension-resistantrelease element may be designed as a separate element, for example inthe form of a line, of a profile body or of a strip. Such release meansmay consist, for example, of plastic or of metal, for example of steel.However, it is also possible for special release means or plasticmaterials to be applied around the microcable, for example a plasticfilm of polyethylene, so that adherence between the microcable and thefilling means occurs only negligibly, if at all. Furthermore, it ispossible for this purpose that the laying channel be filled above themicrocable with a release means which is designed as a filling profileand is pressed into the laying channel, if appropriate with additionalsealing with respect to the borders of the laying channel. Once again, aviscous material such as bitumen is particularly suitable for thispurpose. Particularly elastic materials, for example rubber or elasticplastics, are suitable for such a filling profile.

[0128] However, the tension-resistant release element may also form aconstituent part of the sheathing of the microcable, it being possiblefor the sheathing material to be separated easily from the microcable,so that, once again, the filling material is first of all removed withthe tension-resistant release element during the lifting operation.

[0129] If the tension-resistant release element consists of electricallyconductive material, it may also be used, in addition, for the powersupply along the microcable.

[0130] It is illustrated in FIG. 23 that a microcable MK is introducedin the cut laying channel VN of the solid ground VG and, according tothe invention, a tension-resistant release element ZT in the form of ametal or plastic line has been arranged above said microcable during thelaying of the same. Above this, the laying channel VN is filled in asealed manner with a filling material FM, for example consisting ofbitumen. Before the microcable MK is lifted, the tension-resistantrelease element ZT is, then, drawn out in order also to remove thefilling means FM from the laying channel VN, this resulting in thelaying channel VN then being free and it being possible to lift themicrocable MK without risk.

[0131]FIG. 24 shows that it is also possible for the laying channel VNto be filled with a tension-resistant filling profile FP, which is drawnout if required. This tension-resistant filling profile FP mayadditionally be introduced with a sealant, for example with bitumen,this resulting in the laying channel VN being sealed reliably.

[0132] The object of a further development of the invention is toprovide a process for the power supply of a minicable or microcable withoptical waveguides. The set object is achieved, by a process of the typementioned in the introduction, in that the metallic tubes of themicrocables or minicables are connected to the central power supply.

[0133] In general, at the present time, the power is supplied by anadditional power cable which is supplied from a central point. Thedisadvantage is that a separate power cable has to be laid over a largedistance. Costs for an additional cable route and voltage losses have tobe accepted. Additional measures for the power supply likewise have tobe taken for the optical-waveguide submarine cable known per se.

[0134] However, a minicable or microcable of the type describedcomprises a tubular metal sheath. This protects the optical waveguidesagainst damage during laying, guarantees a certain excess length of thefibres and is stable with respect to transverse forces. Moreover, thesolid ground in which the laying channel is provided gives the minicableor microcable the necessary protection against external mechanicalinfluences. The electric properties of this minicable or microcable,however, are not utilized. If, then, the metal tubes of these minicablesor microcables are electrically interconnected at the connectinglocations, as is effected, for example, with the aid of metallicconnecting sleeves, this system can be used for a power supply. A secondconductor may provide the return conductor or, if it is insulated, thepower supply. With the return conductor, insulation may be dispensedwith if required. The return conductor may additionally assumeprotective functions.

[0135] Such a minicable or microcable and the power supply may also beproduced as a continuous cable. A separate return conductor can bedispensed with if two insulated microcables are laid. Use may also bemade of two microcable tubes in one microcable with corresponding commoninsulation. The cable sheath insulates the tubes with respect to oneanother and to the earth. Such a minicable or microcable can easily bebent around a narrow axis and laid.

[0136] With such a power supply, the strength and the conductivity arerealized by way of the cross-section of the cable sheath or of themetallic tube. Sufficient electrical interconnection is guaranteed bycrimping metallic sealing heads of a cable sleeve to the metallic tubeof a minicable or microcable. For the return conductor of the powersupply, use may also be made, for example, of cable holding-downdevices, if these consist of metal. The task of these cable holding-downdevices is, in the original sense, to position the cable securely at thecorrect laying height in the laying channel. When direct current isused, it is also possible to dispense with a return conductor ifearthing takes place. If the metallic tubes of the minicables ormicrocables are provided with an insulation layer, then, in addition tothe possibility of insulated power supply, the following advantages canalso be achieved:

[0137] corrosion protection for the metal

[0138] the metal tube is protected against mechanical damage duringlaying

[0139] the insulation layer forms a wear layer for the drawing-inoperation of the microcable

[0140] the insulation layer forms heat insulation when sealing thelaying channel with hot bitumen

[0141] the insulation layer forms vibration insulation in the case ofheavy traffic.

[0142]FIG. 25 shows the through-connection of the power supply with theaid of a metallically conductive cable sleeve KM. The power is suppliedthrough the microcables MK1 and MK2, the ends of which are electricallyinterconnected by the sleeve tube MR. The electric contacting, therelief of tension and the sealing of the microcables MK1 and MK2 takeplace at the crimp locations of the sealing heads DK. In this case, theouter side of the cable sleeve KM is additionally provided with anelectric insulation IS.

[0143]FIG. 26 illustrates in the position of a microcable MK which[lacuna] in the laying channel VN above a power cable SK provided withan insulation SKI.

[0144] This power cable SK is a single-phase power cable and the tubeMKR of the microcable MK is provided with a plastic insulation IS. Afterthe introduction of the cables, the laying channel VN in the ground VGis filled with a sealing compound VM. The power is thus supplied via theinsulated microcable MK and the insulated power cable SK.

[0145]FIG. 27 shows the arrangement of a non-insulated microcable MKwith its metallic tube MKR, in which the optical waveguides arearranged, above an insulated power cable SK, within a laying channel VN.The single-phase power-supply cable SK is, once again, insulated and thenon-insulated tube MKR of the microcable MK is earthed. In this case, aninsulation can be dispensed with.

[0146]FIG. 28 shows the power supply through a microcable MK whose tubeMKR is provided with an insulation IS. Above this, an earth strip, asreturn conductor RL, ensures the return conduction. In this case, thereturn conductor RL serves simultaneously as additional protection forthe microcable MK.

[0147]FIG. 29 shows the laying of a microcable provided with insulationIS, in which case a continuous cable holding-down device NH secures theintroduced cable MK in its vertical position. The cable holding-downdevice NH has obliquely positioned side walls NHS which are supportedagainst the wall of the laying channel VN. In this case, returnconduction of the power supply takes place via the cable holding-downdevice NH, which serves moreover as an upward protection and guard.

[0148]FIG. 30 illustrates the power supply through a microcable MK whichis arranged, with an additional wire ZS, with an insulation IS. Saidadditional wire ZS is electrically insulated with respect to themicrocable MK. Moreover, the material of the additional wire isdetermined such that it can be used as a supporting wire with thenecessary nominal tensile force. It consists, for example, of steel orbronze.

[0149]FIG. 31 shows the power supply, once again, via a microcable MK.An additional wire ZS is integrally moulded on the microcable MK via aninsulation IS, the connection between the two taking place via a web ST.The microcable MK may be separated from the additional wire ZS in theregion of the web ST if required. Such a separation is practical, forexample, for bridging connecting sleeves.

[0150]FIG. 32 shows the arrangement of two microcables MK1 and MK2located one above the other in the laying channel VN. The twomicrocables MK1 and MK2 are insulated separately and can be laidseparately from one another or together. Each microcable may expedientlybe spliced to a single sleeve and electrically interconnected.

[0151]FIG. 33 shows the power supply through two microcables MK1 and MK2which are located one above the other and are insulated separately, butare connected to one another via a web ST. For splicing, the microcablesMK1 and MK2 can be separated from one another in the region of the webST, with the result that each microcable MK1 or MK2 can be spliced indifferent single sleeves and electrically interconnected.

[0152] The object of a further development of the invention is to find aprocess with the aid of which a laid minicable or microcable can belocated. The set object is, then, achieved, in accordance with processof the type mentioned in the introduction, in that the route of theoptical minicable or microcable laid in a laying channel is followedwith the aid of a detector.

[0153] Advantages of the invention over the prior art can be seen, inparticular, in that, with the aid of a detector, the laid minicable ormicrocable can be traced so accurately that, for example, it can even beentered, with relatively low tolerances, for archiving in town streetplans and cable-route plans. The process using a detector according tothe invention can also be used to locate the cable in the ground forrepair purposes, it being possible for interruptions in the cable to belocalized accurately. It is just as important, before the laying channelis cut, to check the route as to whether or not there are already supplylines in the ground. Such a process, which is based on the operation ofsuitable detectors, can thus be used for the acceptance and approval ofa new cable route, since the quality of laying and the laying depth canbe established at any time.

[0154] It is thus expedient to arrange such a detector, as a functionalunit for locating cables, in front of a joint-cutting machine, so thatany metallic object, for example a cable or supply line, which islocated in the ground, is detected in each case. For laying minicablesor microcables, detection can take place via the metal tube itself, viaa return conductor which is carried along or else via cable holding-downdevices in the laying channel. These cable holding-down devices may alsobe used, for example, for the power supply and for a protective functionfor locating the minicable or microcable. It would be possible forholding-down devices to have a fixedly predetermined code or else to befreely programmable. A service vehicle which is used to trace the laidcable is expediently made available for this process. This unit producesthe reference for a marking points, and stores the route in which theoptical cable is laid, so that the route can be transferred ontoexisting street plans. In this way, both the position and the depth ofthe laid microcable can be established.

[0155]FIG. 34 describes the principle of the process for locating anoptical cable, in particular a minicable or microcable, with the aid ofa detector D which is accommodated in a service vehicle. When thisvehicle drives over a laying channel VN, it is established by way of theemitted and reflected locating signal OS that a laying channel VN hasbeen driven over. In this exemplary embodiment, the microcable MK hasbeen laid in the laying channel VN, and the laying channel VN has thenbeen filled with filling material, for example bitumen, metallic fillershaving been added to the filling material.

[0156]FIG. 35 shows a longitudinal section through a laying channel VNin solid ground VG. The microcable MK is introduced at the base of thelaying channel and is held in position with the aid of cableholding-down devices NH, which are of a dowel-like design. Theindividual cable holding-down devices NH are provided with magnets whosemagnetic fields can be located by the detector passing over them. Thealignment of these magnets may be the same or else alternately differentin all of the cable holding-down devices NH. Alternate alignment of themagnets M with the poles MN and MS can produce a system of alternatemagnetic fields by means of which it is even possible to establish acoding for the laid minicable or microcable. The laid cables can beidentified accurately in this manner, with the result that it ispossible to rule out mix-ups during repair work.

[0157]FIG. 36 illustrates a laid microcable MK, in the laying channelVN, which is held in position by magnetic cable holding-down devicesNHN. Here too, poles of the magnetic cable holding-down devices NHM maybe clamped in the laying channel VN with alternate orientation of themagnet poles NHMN and NHMS, so that coding of the cable route ispossible in this case as well. The U-shaped cable holding-down devicesNHN wedge in during laying and are supported on the channel wall. TheU-shaped cable holding-down devices are magnetically insulated withrespect to one another and are pressed in individually by thecable-laying machine. These magnetic cable holding-down devices NHM maybe permanently magnetic or magnetized individually during laying. Heretoo, the magnetic field can be detected through the filling material,which is not illustrated in this case.

[0158]FIG. 37 illustrates, once again, a microcable MK laid in a layingchannel VN, this microcable being held in position by bar-like cableholding-down devices SNHM. These bar-like cable holding-down devicesSNHM likewise wedge in during laying and are supported against thechannel wall. Once again, the bar-like cable holding-down devices SNHMare magnetically insulated with respect to one another, and may bepermanently magnetic or only magnetized individually during laying. Heretoo, it is possible to allocate an individual coding (morse) to eachlaid optical cable by alternating the magnet poles. It is also possiblein this case, in the manner described, for the magnetic field to bedetected by a detector in accordance with the process according to theinvention.

[0159] A grid-like cable holding-down device GNH is illustrated in FIG.38. Here, the bar-like, magnetic cable holding-down devices SN, HM arefastened on two longitudinally running support filaments TF, theindividual bar-like, magnetic cable holding-down devices SNHM beingmagnetically insulated from one another. During the laying operation,this grid-like cable holding-down device GNH can be easily unwound andintroduced above the cable in a clamping manner. Such a structure canalso be used in a simple manner to measure the length of the cable routesince a kind of graduated scale is provided by the uniform spacing ofthe bar-like cable holding-down devices SNHM. The individual bar-likecable holding-down devices SNHM may be permanently magnetic or onlymagnetized individually during laying. Here too, it is possible toprovide a coding by alternating the magnet poles.

[0160]FIG. 39 illustrates that the cable holding-down devices KNHM canbe, as it were, tacked or clamped onto the support filaments TF. Thismay also take place on site, in which case any desired coding patterncan be produced. Such a coding may also take place, for example, byvarying the spacing between the individual bar-like, magnetic cableholding-down devices KNHM.

[0161] It is illustrated in FIG. 40 that the cable holding-down devicesENHM may also have their ends E fitted onto a support sheet TFOL. Heretoo, it is possible to vary the polarity and the spacing of theindividual bar-like cable holding-down devices ENHM for a correspondingcoding. During filling of the laying channel with hot bitumen, the sheetthen melts, with the result that the hot bitumen can fill the layingchannel between the bar-like magnets ENHM. The bar-like cableholding-down devices ENHM remain wedged in the laying channel and holdthe microcable in the corresponding position.

[0162] In addition to the abovedescribed possibility of purely passivecoding by cable holding-down devices NH, an active coding provided byelectronic components is illustrated in FIG. 41. FIG. 41 is derived fromFIG. 35. However, the magnets have been replaced by electronic pulsegenerators I. The information of the pulse generators I can beinterrogated from the road surface by a movable induction loop IS.

[0163] The pulse generators I can emit cable-specific information, e.g.operator name, route to which the relevant cable belongs, laying depth,laying date, number of optical waveguides, etc.

[0164] A freely programmable chip C which is assigned to the microcableMK or to the holding-down device NH is illustrated in FIG. 42.

[0165] It can store and reproduce information (cable, sleeve, operator,free optical waveguides, etc.). Interrogation can take place inductivelyvia the support filaments (TF) or by electrically contacting the cablesheath or the carrier filaments from the sleeve.

[0166] In FIG. 43, the programmable chip CH is accommodated in thesleeve M, so that information can be emitted from the sleeve. It is alsopossible for further electronic active components to be accommodatedhere. The power supply can take place from here, it also being possiblefor the support surfaces TF of the cable holding-down devices NH to bedesigned, for example, as power-supply conductors.

[0167] The abovementioned optical cables are referred to as microcablesand are preferably laid in laying channels in solid ground. On accountof their small diameters, the laying channels can be kept very narrow,so that they can be produced with the aid of cutting processes.Particularly suitable laying surfaces are substructures and roadsconsisting of asphalt or concrete. The laying depth is very small and isbetween 7.5 and 15 cm. Such optical-waveguide cable systems areparticularly wellsuited for laying in surfaces which have already beenestablished for this purpose, since high-outlay excavation work does nothave to be carried out. Moreover, the laying time is very short, whichis particularly advantageous in the case of roads. After theintroduction of the microcables into the cut laying channels, these arefilled with suitable filling material, for example with bitumen. Furtherexamples of suitable laying channels are expansion joints which areprovided between individual concrete slabs or are provided as aprecautionary measure in concrete slabs for road surfaces. Microcablesmay likewise be laid in these expansion joints. These expansion jointsare likewise filled with filling material, so that the microcables areprotected.

[0168] However, it must also be possible for such microcables to belifted, for example when repair work has to be carried out on the tube.These microcables cannot, however, be removed from the laying channeltogether with the filling material since the forces required for thispurpose would damage the microcable further. Moreover, the tube has tobe restored in the region where damage has been established and thenintroduced into the laying channel again.

[0169] A further object of the invention is to develop a process bywhich it is possible to remove a microcable of the abovedescribed typefrom the laying channel and to repair the same. The set object is, then,achieved, with the aid of a process of the type mentioned in theintroduction, in that, with the aid of a unit for exposing themicrocable, the filling material is removed from the laying channel overa length which is required for the introduction of a repair set, saidrepair set being formed from two cable sleeves, two equalizing loops anda connecting tube between the cable sleeves, in that the microcable islifted from the laying channel freed of the filling material, in thatthe tube of the microcable is shortened over a length which correspondsto the repair set and in that the repair set is connected tightly to thetwo ends of the microcable.

[0170] Microcables of the abovedescribed type are laid in the upperregion of roads and footpaths. In terms of dimensions, they are verysmall and could thus easily be overlooked when earth work is carriedout, so that the possibility of damage is considerably higher than inthe case of conventionally laid communication cables. It is thusnecessary to have a quick process for repairing a damaged microcable, bymeans of which the damage can be rectified in a relatively simple mannerand in a short period of time. A repair set is designed for thispurpose, which set is made up of existing standard parts, that is to sayof two cable sleeves with a connecting tube located therebetween, thisconnecting tube bridging over the length of the damaged area, and of twoconnection units which are connected to the ends of the damagedmicrocable. The damage location, for example a cut-through tube of themicrocable, may be located, for example with the aid of an electric testsignal, by radiation. However, if the tube is still connectedmetallically, the defect location In the optical waveguide has to betraced and localized, for example, with the aid of an Optical TimeDivision Reflectometer (OTDR). In this case, some of the introducedlight is reflected back by way of defect locations in the glass(soiling, splice, etc.). If the transit time is measured, the spacingbetween the defect location and the transmitter can be measured.

[0171] For the repair, the microcable has to be exposed, on either sideof the defect location, to such an extent that there is sufficientexcess length for manipulation and for splicing in the cable sleeves.For this purpose, however, first of all the laying channel has to befreed of filling material since it is not otherwise possible for themicrocable to be lifted without further damage. The laying channel isexposed by cutting out or scraping out—possibly in a number of layers—orby heating the sealing compound, by cutting out and removing with theaid of a cutter guided in the laying channel, or by heating themicrocable or further electrically heat-conductive parts which may belocated in the channel close up beside the microcable.

[0172] In each of the two cable sleeves, which are suitable forreceiving microcables at least in the inlet region, in each case one endof the defective microcable is introduced and is spliced there tooptical waveguides, which are guided to the second cable sleeve via theconnecting tube. These optical waveguides are then spliced, in thesecond sleeve, to the optical waveguides of the second end of thedefective microcable. The cable sleeves are expediently sunk in coreholes which are cut in tangentially beside the exposed laying channel.The inlets of the cylindrical cable sleeves are arranged tangentially onthe sleeve cylinder, with the result that the inlets of the microcableconnections in the form of equalizing loops only have to be deflected toa slight extent. The microcable connections likewise comprise tubes andare designed as equalizing loops, so that it is possible to compensatefor tolerances and longitudinal expansion when the sleeves areintroduced and during operation. The tight connections to themicrocables are produced by crimping the ends of the equalizing loopsonto the ends of the microcable. After these operations, the layingchannel can be filled with filling material again.

[0173] A break KB in a microcable NK is illustrated in FIG. 44, thefilling compound having already been removed from the laying channelover a length which is necessary for the repair. All that is left in theexposed laying channel FVN, which is provided, for example, in a solidroad surface VG, is a small layer of filling compound above themicrocable NK, which layer of filling compound, for safety reasons, isnot removed in its entirety, so that the microcable MK is not damagedmechanically by the tool. An appropriate control means as is furtherexplained at a later point in the text is suitable for this purpose. Thelaying channel with the virtually exposed microcable MK is thenaccessible from the road surface SO, so that the two ends of themicrocable MK which is to be repaired can then be removed simply andcarefully.

[0174]FIG. 45 illustrates the already outlined process for repairing amicrocable MK which is broken at the location KB, the exposed layingchannel FVN being viewed from above in this case. It can be seen thattwo core holes B have been drilled vertically into the ground, virtuallytangentially beside the exposed laying channel FVN, at a spacing whichis required for the excess lengths of the optical waveguides, and acylindrical cable sleeve KM has been introduced into each of the coreholes. These cable sleeves KM are designed for receiving microcables andhave tangentially running cable-sleeve inlets KE to which tubularequalizing loops AS are connected. The diameter of these tubularequalizing loops AS is adapted to the diameter of the microcable MK, thetight connections usually taking place by crimping AK. The equalizingloops AS serve for equalizing tolerances and expansions. Since the cablesleeves KM have tangential cable inlets KE, the equalizing loops AS canbe fitted on with only small bends, so that they can be run into theexposed laying channel FVN without buckling or stressing.

[0175]FIG. 46 shows the arrangement in accordance with the outlinedrepair process and constitutes a longitudinal section of the arrangementaccording to FIG. 45, for the sake of simplicity the cable sleeves beingillustrated in a sectional and simplified form in order better to showthe conditions. It can thus be seen that the equalizing loops AS areconnected by means of crimping AK, on the one hand, to the tube ends ofthe microcable MK which is to be repaired and, on the other hand, to thecable inlets KE of the cable sleeves KM. The optical waveguides LWL ofthe microcable MK are each fed to the corresponding cable sleeve KM byway of the equalizing loops AS and, there, are spliced, at splicingunits SK, to optical waveguides LWL which lead, via the connecting tubeVR, to the respectively second cable sleeve KM. All the connections canbe restored in this manner. After the cable sleeves KM have been closedoff, the previously exposed laying channel FVN can be filled withfilling material again.

[0176]FIG. 47 shows a unit GF for removing the filling compound FM fromthe laying channel VN provided in solid ground VF. A microcable MK islaid at the base of said laying channel VN and has to be lifted, forexample, due to a break in the tube. In this case, the microcable MK isprovided with an insulation layer IS. For the purpose of removing thefilling compound FM, use is made, in this process, of a heated cutterSCH which is mounted cardanically, that is to say rotatably, at a pivotpoint DP of the unit GF and thus compensates for inaccuracies in theguidance of the cutter. Also provided is a spring mechanism F which isdesigned such that the cutter SCH can tilt out upwards if thelifting-out force exceeds an adjustable value. This cutter SCH ismounted on a mobile unit GF and is heated, for example, from a containerfor fuel BS via a connecting line SH. A motor M ensures that the unit GFadvances above the laying channel VN on the road surface. An electricmeasuring device MV is used, during the process, to monitor that themicrocable is not additionally damaged by the cutter SCH beingintroduced too deeply, the tube of the microcable MK and the metalliccutter SCH being connected to a continuity tester. If, then, theinsulation layer IS is damaged by the cutter SCH, the measuring deviceMV responds and the depth of engagement of the cutter SCH may then becorrected. It is also possible for the exposing operation to take placein layers.

[0177] Further aids may also be provided in order to expose themicrocable in the laying channel. Thus, for example, the insulation ofthe microcable may be designed as a type of zip fastener, so that thetube itself does not come into contact with sealing material when thelatter is being introduced. After the filling material has been removedand the “zip fastener” has been opened, the microcable can be completelyfreely removed from the insulation. Furthermore, it is also possible fora ripping wire to be introduced into the laying channel above themicrocable, it being possible for this ripping wire to be used forpulling out the filling material. If continuous cable holding-downdevices have been introduced above the microcable during the layingoperation, these cable holding-down devices may also be used forremoving the filling material.

[0178] If the microcable has an insulation, this insulation is extremelysuitable as a release means between the metallic tube of the microcableand the well-adhering filling material (for example bitumen) which sealsthe laying channel. A cable sheath consisting of polyethylene, paper ora swelling nonwoven acts as a zip fastener as the microcable is exposed,since those materials do not adhere to the tube but adhere well to thebitumen. Such a cable sheath thus acts as a release means between themetal tube and the filling material. The metal tube of the microcableshould have a smooth surface in order to reduce the adherence. Thelaying channel is exposed in the abovedescribed manner, but theinsulation remains in the laying channel.

[0179] It is also possible to lay a strand of foam rubber GU as releasemeans between the microcable MK and the filling material FM, as is shownin FIG. 48. In such an arrangement, the cutter of the laying unit wouldthen not have to be heated. It is also possible to use a particularlystrong cable sheath. In addition, the cable sheath may also bethickened.

[0180] In accordance with the same process, it would also be necessaryto remove a filling material from a laying channel which are introducedbetween the individual slabs of a concrete roadway or in expansionjoints of slabs on which it is possible to drive. It would thereforealso be possible to dispense with the operation of introducing anadditional channel with the aid of a cutting blade in the case ofconcrete roads. If these channels in the concrete have a dimension whichcorresponds approximately to the diameter of a microcable, such cablescan be introduced into these already existing channels without furthermeasures being taken. These channels are then likewise filled withfilling material and sealed. Since such seals in the channels of theconcrete slabs have to be renewed at certain time intervals for safetyreasons, there is the opportunity to use such occasions to lay newmicrocables without additional cost, time-saving also playing a rolehere. Moreover, the road structure would not be weakened by additionallaying channels for the microcable. It would be possible for theexpansion joints to be made deeper or wider by abrasive grinding.

[0181] Concrete roadways are divided up, directly after casting, bydummy joints into individual slabs of a size of from 7.5 m to 20 m.These dummy joints are predetermined breaking points which are producedby cuts of a depth of approximately 5 to 10 cm and a width ofapproximately 8-10 mm. Sealing strip, foam rubber or filling bitumenseal the dummy joints against dirt and surface water. Such channels arelikewise suitable for the laying of microcables. In order to protect themicrocables laid therein and in order to be able to compensate forirregularities caused by the soil mechanics, it is expedient to widenthe dummy joint at each concrete-slab joint, so that the microcable hassufficient opportunities for compensation in these areas. For thispurpose, a core hole with a diameter of 8 to 10 cm would be sufficientin order to protect the laid microcable when roadway slabs are displacedwith respect to one another by subsidence, earthquakes or similar groundmovement. Shearing off or buckling of the laid microcable could thus belargely ruled out.

[0182] The length of the repair set depends on the damage location. Inorder to have sufficient excess length of fibre, a fibre supply ofapproximately 1.5 m has to be allowed for each sleeve. The connectingtube VR, and thus the length of the repair set, is always 3 m longerthan the defect location which is to be bridged.

[0183] The filling material can also be heated, for example, by heatingcurrent-carrying conductors which have been introduced in the fillingmaterial. The cable holding-down devices, for example, can be used forthis purpose.

[0184] The object of a further development of the invention is toprovide a process in which the microcable is fixed continuously alongits length during the laying operation.

[0185] The set object is, then, achieved, by a process of the typementioned in the introduction, in that the microcable is fixed in alaying channel in the ground with the aid of a continuous profile bodyconsisting of elastic material, and in that the laying channel is sealedby introducing a sealant.

[0186] The microcable, then, is fixed, in a simple manner and ideallyfollowing the laying of the microcable in the laying channel, byintroducing a continuous profile body at the base of the laying channel.The continuous, elongate profile body preferably comprises an extruded,rubber-like plastic, which is usually referred to as foam rubber. Theaction of pressing this profile body into the laying channel deforms itelastically and, due to the elastic prestressing, wedges it against thewalls of the laying channel. In so doing, irregularities are compensatedfor by the elastic material. The material consists of a rot-proof softrubber which is resistant to temperature and UV. If required, thisprofile body may additionally be sealed at the top with a sealant, forexample with hot bitumen. In this way, the profile body is additionallyfixed mechanically in the channel. This gives the following advantagesover holding-down devices comprising metal clamps or similar elements:

[0187] Less hot bitumen is required for the sealing.

[0188] The profile body is laid quickly, in some circumstancesimmediately after.

[0189] The laying operation can run continuously.

[0190] This alone provides rough sealing with respect to surface water.

[0191] The elastic material of the profile body can allow for expansionsin the ground.

[0192] There is only slight shrinkage of the hot bitumen in the sealingarea, so that there is hardly any “subsequent settling”.

[0193] The channel filling, comprising the profile body and the sealant,can be easily removed again since a type of zip-fastener function is setup.

[0194] The main purpose of the invention, however, is to fix themicrocable in the laying channel with the aid of a profile body.Furthermore, the channel is sealed towards the road surface and thecable is protected against mechanical loading and vibration.

[0195] In the simplest exemplary embodiment, use is made of an elasticprofile body with circular cross-section which is pressed in directlyabove the microcable, for example using a roller or roll, the remainingfree space in the laying channel being sealed off towards the top with ahot bitumen. On account of its elastic properties, pressing in of theprofile body also fills the cavities between the microcable and thelaying walls.

[0196] An exemplary embodiment in which the microcable is alreadysheathed with an elastic profile body is also advantageous.

[0197] However, use may also be made of dimensionally stable,elastically deformable sealing profiles, which then have deformableformations, for example barbs, which make it possible for said sealingprofiles to clamp and catch on the channel walls and irregularities inthe laying channel.

[0198] As sealant for sealing the laying channel against the penetrationof water, use is preferably made of heats-softenable materials, forexample fusible bitumen or hot bitumen or hot-melt adhesives known perse, e.g. consisting of polyamide. These sealants are introduced, underthe action of heat, after the microcable has been laid in the layingchannel, said laying channel then being sealed after setting of thesealants.

[0199] Use may also be made of temperature-resistant and dimensionallystable profile bodies in which there are arranged free ducts into whichmicrocables or else free optical waveguides are drawn. The opticalwaveguides are introduced, then, for example by cables, fibres or fibreelements being blown or drawn in, it being possible for these operationsto take place before or else after the introduction of the profile body.

[0200] It is thus possible for a microcable to be fixed in its layingchannel in a simple manner by a continuous profile body, the out layingchannels in the solid ground, for example a road, being closed off in awater-tight manner. The microcables can be laid better using suchprofile bodies and, in the event of a repair being necessary, theseprofile bodies can be easily removed again from the laying channel. Theprofile bodies which are introduced above the microcable simultaneouslyprotect against high temperatures (from 230 to 280° C.), which may occurwhen the hot bitumen or the hot-melt adhesive penetrates. Moreover, itis also possible for the profile bodies to compensate, to some extent,for changes in length in the case of irregularities in the road(subsidence) or in the case of different thermal expansions of cable androad surface.

[0201] However, the microcables may also be provided during manufacturewith a sheath consisting of soft, as far as possible cellular orexpanded plastic, so that this sheath already assumes the function ofthe profile bodies. Such a microcable is then held down by the appliedsheath, which is compressed in the same manner against the channelwalls.

[0202] The profile bodies may thus be introduced into the laying channelas an endless profile without any joints, the profile bodies expedientlybeing brightly coloured, so that they simultaneously provide a warningfor subsequent roadworks. Moreover, the microcable is elastically sealedtowards the top, so that the microcable is isolated from mechanicalloading (vibration). Using a profile body which completely encloses themicrocable provides a uniform radial pressure, with the result that thecable is aligned without stressing. Since the elongate profile bodieshold the microcable down uniformly, it is no longer possible for themicrocable to rise up due to inherent stressing of the same. Moreover,the microcable is not subject, during laying, to any longitudinalstressing, which could possibly lead to expansion or tensile stressingof the optical fibres. During the laying operation, the microcable isrouted very accurately, so that the cable cannot deflect or buckle underthe thermal or mechanical loading. Furthermore, pressing the profilebodies into the laying channel results in gap-free filling of theinterstices in the vicinity of the channel wall on account of theirelastic properties.

[0203] The microcable may have a sheath extruded on it as early as theproduction stage. However, it is also possible to apply a cylindricalsheathing subsequently, shortly before the microcable is laid, saidsheathing preferably being slit, so that it can be latched onto themicrocable.

[0204] The introduced profile bodies can be cut out in a simple manner,during repair work, with the aid of a chisel or knife, so that themicrocable which is to be repaired can be lifted in a simple manner.

[0205] It is also possible for a plurality of microcables to be arrangedone above the other in one laying channel, this providing thepossibility of using a profile body which has a plurality oflongitudinally directed free ducts.

[0206] It is also possible for further microcables to be introducedsubsequently into a laying channel, in which case the profile body isfirst of all removed in order to provide space for the furthermicrocable. A profile body is then subsequently pressed in and is, onceagain, closed off towards the top with a sealant.

[0207] If use is made of relatively hard profile bodies, additional freeducts may run in the longitudinal direction, it being possible forfibres to be provided therein, for example blown in, at a later point intime.

[0208]FIG. 49 shows a laying channel VN in solid ground VG, for examplea road surface. The microcable MK has already been introduced in thebase of said laying channel VN. As the arrow GK indicates, a continuousprofile body GU consisting of elastic material, for example rubber, hasbeen introduced above the microcable MK as a holding-down device for thesame.

[0209]FIG. 50, then, shows that the action of pressing in causes theprofile body GU to mould to the microcable MK and the channel wall NW.The rest of the laying channel is filled in a sealed manner towards thetop, up to the road surface SO, with a sealant B, for example ahot-melting bitumen.

[0210]FIG. 51 shows, schematically, the operation of a laying unit VW.The microcable MK is unwound directly from a drum TMK on the left-handside, so that the microcable can be laid easily in the laying channel.Unnecessary deformation of the microcable is avoided in this case. Alaying shoe VS avoids the situation where the microcable MK rises up outof the laying channel. Provided on the right-hand side of the layingunit VW is a second drum TGU for the profile body GU which iscontinuously pressed into the laying channel VN above the microcable MKby a pressure-exerting roller AR. In this way, in a laying operation,the microcable MK is laid in the laying channel VN, and fixed by theprofile body, in a simple manner. The laying shoe VS is held in positionwith the aid of a spring structure F, and a braking device BR ensures adefined drawing-off speed for the two drums TMK and TGU. Finally, thelaying direction VR is indicated by an arrow.

[0211]FIG. 52 shows a microcable MK which has already been provided withan elongate, annular profile body GUR. This profile body can either beextruded onto the microcable MK during production or be drawn onsubsequently. If the profile body GUR is drawn on subsequently, it isexpedient to provide a longitudinal slit S, so that the profile body GURcan be latched onto the microcable MK by expansion. The edges of thelongitudinal slit S are expediently bevelled, to render the latching-onoperation easier.

[0212]FIG. 53 shows a laid microcable MK with a profile body GUR drawnthereon, the pressing-in operation deforming said profile body such thatcavities are largely eliminated. In this embodiment, furthermore, anadditional profile ZP which additionally closes off the laying channeltowards the top is introduced. The two profile bodies consist ofelastically or plastic material, so that they lend themselves well todeformation. The rest of the laying channel VG is, once again, closedoff and sealed with a sealant, for example hot bitumen B. If it isintended to lift a microcable MK again, then a chisel is used to removethe sealant B mechanically and extract it from the laying channel. Sinceit is only the sealant and the channel wall which adhere firmly to oneanother, the profile body can be easily drawn out after removal of thesealant. As a result, the microcable MK which is to be repaired isfreely accessible again.

[0213]FIG. 54 shows the cross-section through an elongate profile bodyVP comprising a solid profile which has elastic properties, but cannotbe deformed plastically. The profile body is fixed in the laying channelby elastic barbs WH. Arranged within the profile body VP arelongitudinally running free ducts FK into which fibres can be drawn orblown at a later point in time. Provided in the upper region of theprofile body VP is a duct for a microcable MK which is introduced intothe profile body VP in the direction GR, through a longitudinallyrunning slit VPS, before the laying operation.

[0214]FIG. 55 shows the profile body VP of FIG. 54 within the layingchannel VN, the elastic barbs WH having been wedged along the channelwall. Additional optical waveguides may possibly be drawn or blown intothe free ducts FK of the profile body VP at a subsequent point in time.The upper part of the laying channel VN is, once again, filled with asealant B.

[0215]FIG. 56 shows a cross-section of a profile body P which likewisehas elastic properties, but cannot be deformed plastically and hasalready been sheathed at the factory with a fusible sealant BVP, forexample consisting of hot bitumen or hot-melt adhesive. This groovedmoulding NFT is heated before laying, so that it can be rolled into thelaying channel in the hot state. Free ducts are, once again, provided inthe profile body P, but a slit duct for receiving a microcable may alsobe provided here.

[0216]FIG. 57 shows the laying operation for a grooved moulding NFTaccording to FIG. 56. Here, use is made of a hot roll WW which pressesthe heated grooved moulding NFT into the laying channel VN. The sealantsheathing the profile body is expediently heated by heat radiation WSfrom infrared radiators IS. Before laying, the laying channel VN is alsoheated in order to avoid overly rapid cooling of the sealant. Finally,the excess sealant is rolled in at the road surface and removed.

[0217] Furthermore, the object of one development of the invention is tofind a process in which the laid minicable or microcable is sufficientlyprotected against damage by the penetration of pointed implements andvery sharp-edged objects. The said object is achieved according to theinvention, with the aid of a process for introducing an optical cable ofthe type mentioned in the introduction, in that, after the introductionof the minicable or microcable into the laying channel, an elastic,notch-impact-resistant covering profile which is difficult to cutthrough by mechanical intervention is laid in the longitudinal directionof the minicable or microcable, and in that the width of the layingchannel is covered in so doing.

[0218] The advantages of the process according to the invention forlaying optical-waveguide cables, in particular minicables ormicrocables, consists essentially in that as early as at the actuallaying stage itself additional protection is afforded for theoptical-waveguide cable against accidental or intentional mechanicalintrusion into the laying channel. Such intrusion in the route mayoccur, for example, deliberately as a result of vandalism oraccidentally as a result of work being carried out in the ground there.Thus, for example, in the case of the penetration of a pointed and verysharp-edged object, for example a screwdriver or chisel, penetration asfar as the microcable is prevented. This results in elastic/plasticdeformation of the tough and resilient covering profile, whichcomprises, for example, a metal-wire core and an elastic sheathingconsisting of plastic material. Intermediate coverings which rundirectly above the microcable may additionally be introduced during thelaying operation. Wires for reinforcing the mechanical strength andsensors for information which is to be called up may additionally beintroduced into these intermediate coverings. Such sensors may be used,for example, to locate and monitor disruption-free operation. Thetoughened resilient core essentially prevents the penetration with asharp-edged object. The foam sheathing, on the other hand, cushions theadditional loading and distributes the compressed loading over a largesurface area, so that the minicable or microcable is not deformed ordamaged any further. In addition, this also provides a simple liftingaid for the optical-waveguide cable, since the tensile strength of thecovering profile is sufficient for removing from the laying channel thefilling material which is located above said covering profile. Thecovering profile also serves, at the same time, as the holding-downdevice for the optical-waveguide cable in the laying channel and, in thecase of metal inserts, can also function as an earthing strip.

[0219]FIG. 58 illustrates the cross-section of a laying channel VN, atthe base of which a microcable MK is laid. An intermediate covering ZWAis additionally introduced, after or during the laying of the microcableMK, on said microcable MK located beneath it. This additionally producesbuffering against mechanical action from above, with the result thatdirected blows with a tool or similar pointed object cannot deform oreven cut through the microcable MK. Said intermediate covering ZWA may,if appropriate be provided with inserts ZWE, for example with metallicwires, or with sensors. Such sensors can be used at a later point intime to locate the cable routing as well as penetrating water ordisruptions in the road structure and to trace the intrusion. With anintermediate covering ZWA consisting of conductive material, it is alsopossible for the tube MKR of the microcable MK to be manufactured fromplastic instead of metal, it being necessary for the correspondingboundary conditions as regards tensile strength and transversecompressive strength to be observed. The covering profile AP on whichthe invention is primarily based is then likewise introduced above thisintermediate covering ZWA after or during the introduction of themicrocable. Said covering profile AP may, in principle, be designed as ametal-wire, plastic, hemp or sisal line, it being necessary for thematerial used to have the corresponding properties. This means that thecovering profile AP has to be designed so that it is difficult to cutthrough, can be deformed mechanically to a limited extent and is toughand resilient, which can be achieved, for example, by strandingindividual elements. However, it is advantageous if such an element iscoated, as core MFK, with an elastic sheathing APU, preferablyconsisting of foam material, it being necessary for the diameter of theoverall covering profile AP to correspond to the width of the layingchannel VN, such that clamping in the laying channel is also achievedtherewith. The core MFK itself has to have a thickness which correspondsat least to the diameter of the microcable, so that the covering profileAP with its core MFK provides the microcable MK with full coveredprotection. The rest of the laying channel VN is filled towards the top,towards the surface of the ground VG, with a filling material,preferably with hot bitumen. Such a covering profile AP thus providesconsiderable protection against accidental or intentional penetration ofdestructive objects into the laying channel VN, the tough and resilientcore MFK largely preventing the penetration of a sharp-edged object. Inthis case, the sheathing APU consisting of elastic material cushions theloading and distributes the compressive loading over a large surfacearea. The microcable MK located therebeneath is not deformed or damaged.However, the intermediate covering ZWA shown in this figure does nothave to form part of the arrangement if the covering profile AP meetsthe required conditions itself. Moreover, the mechanically strongstructure of the covering profile AP may also be used as a simplelifting aid for the microcable MK since, on account of the highmechanical strength, it can be used, if required, to draw out from thelaying channel VN the filling material FM located thereabove.

[0220]FIG. 59 illustrates assumed mechanical loading by a pointed objectSG which is driven with a force P into the laying channel filled withthe filling material FM. In this operation, the filling material FM isdisplaced and the object SG comes into contact with the elasticsheathing APU of the covering profile AP. In this case, the sheathingAPU is deformed, or even cut through, but the pointed object SG thencomes up against the core MFK, which is difficult to cut through, of thecovering profile AP, where it is finally stopped. That side of thesheathing APU which in located therebeneath is deformed by the pressureproduced, and a distribution of pressure takes place. The microcable MKlocated therebeneath, which in this case is arranged beneath theintermediate covering ZWA, is thus not damaged.

[0221]FIG. 60 illustrates the operation according to FIG. 59 incross-section. It can clearly be seen that, when it comes into contactwith the covering profile AP, the pointed object SG deforms, or elsecuts through, the sheathing APU and is then prevented from advancingfurther by the core MFK, otherwise, the conditions correspond to FIG.59.

1. Process for introducing an optical cable, consisting of a tube andoptical waveguides introduced therein, into solid ground with the aid ofa laying unit, characterized in that the optical cable laid is amicrocable or minicable (1) with an external diameter of the tube (8) of2.0 to 10 mm, preferably of 3.5 to 5.5 mm, the tube (a) beinghomogeneous and pressurized-water-tight, in that the laying channel (19)with a width of 4.5 to 12 mm, preferably 7 mm, which is adapted to thediameter of the microcable or minicable (1) being made in the fixedunderlying laying surface (17) using the laying unit (23), in that themicrocable or minicable (1) is introduced into the laying channel (19)by means of a feed element and is held at a constant laying depth, inthat the laying channel (19) is filled with filling material (20) with afilling device (16) which is moved on to the insertion of the microcableor minicable (1).
 2. Process according to claim 1, characterized in thatthe optical waveguides (3) are introduced at the factory.
 3. Processaccording to claim 1, characterized in that the optical waveguides (3)are blown into the already laid tube (8).
 4. Process according to claim1, characterized in that the optical waveguides (3) are jetted into thealready laid tube (8) with the aid of a liquid medium.
 5. Processaccording to one of the preceding claims, characterized in that thelaying channel (19) is milled in a supporting laying (47) of theunderlying laying surface (17), in particular a carriageway, using amilling wheel (15) which is arranged in the laying unit, and in cleaned,preferably using compressed air.
 6. Process according to claim 5,characterized in that the laying channel (19) is cut to a depth of from50 to 100 mm, preferably 70 mm.
 7. Process for introducing an opticalcable, consisting of a tube and optical waveguides introduced therein,in supply lines in a solid underlying laying surface with the aid of alaying unit, characterized in that, as optical cable, a microcable orminicable (1) with an external diameter of the tube (8) of 2.0 to 10 mm,preferably of 3.5 to 5.5 mm, is pressed into utility lines (31) forsewerage, gas or water, which have been left open, using a laying unit.8. Process for introducing an optical cable, composed of a tube andoptical waveguides, introduced therein, into supply lines in a solidunderlying laying surface with the aid of a laying unit, characterizedin that, as optical cable, a microcable or minicable (1) with anexternal diameter of the tube (8) of 2.0 to 10 mm, preferably of 3.5 to5.5 mm, is inserted into existing, active utility lines (35) forsewerage, gas or water, using a laying unit.
 9. Process according to oneof claims 1 to 4, characterized in that the microcable or minicable (1)is pressed into the solid ground (17) by means of a laying unit. 10.Process according to one of claims 1 to 4, characterized in that themicrocable or minicable (1) is jetted into the solid ground (17) bymeans of a laying unit.
 11. Process according to claim 1, characterizedin that the microcable or minicable (1) is introduced into the layingchannel (19) with a feed element in the form of a laying blade (18), inthat the filling material (20) is filled in using the filling device inthe form of a filling-in lance (16), and in that the laying channel (19)is topped of f at the road surface with a sealing layer (50). 12.Process according to claim 11, characterized in that a curable fillingfoam is introduced, as filling material (20) into the laying channel(19).
 13. Process according to claim 11 or 12, characterized in that thelaying channel (19) is filled with a bitumen sealing compound or apreformed bitumen joint filler.
 14. Process according to one of claims11 to 13, characterized in that the laying channel (19) is marked by alight-reflecting layer (64), preferably with embedded glass bodies (65)as filling means.
 15. Process according to one of the preceding claims,characterized in that the microcable or minicable (1) is drawn off froma ring wound up on a laying reel (24) and, prior to the introductioninto the laying channel (19), is aligned and levelled parallel to theroute of the laying channel (19) with the aid of guide rollers (25). 16.Process according to one of the preceding claims, characterized in thatin the case of changes in direction and bends up to minimum radii of 30mm of the laying channel (19), the microcable or minicable (1) isadapted to the directional route in a bending apparatus (61). 17.Process according to one of the preceding claims, characterized in thatthe tube (8) of the microcable or minicable (1) is lengthened, ifrequired, via connecting elements which are known per se, for examplesleeves, crimpable tubes or fittings.
 18. Process according to one ofclaims 1 to 16, characterized in that the tube (8) of the microcable orminicable (1) is lengthened, if required, with the aid of adhesiveconnections, solder connections or weld connections which are known perse.
 19. Process according to one of the preceding claims, characterizedin that excess lengths of the microcable or minicable (1) in the form ofequalizing loops (66) are laid in the cable-laying route.
 20. Processaccording to claim 11, characterized in that the laying channel (19) isarranged in the side of the roadway, in the cycle path or footpath, onor in kerbstones or along the fronts of houses.
 21. Process according toone of claims 1 to 5 or 11 to 20, characterized in that holding-downelements (52, 57) are pressed into the laying channel (19) after theintroduction of microcable or minicable (1).
 22. Process according toclaim 21, characterized in that U-shaped, spreadable clamps (52) arepressed into the laying channel (19).
 23. Process according to claim 21,characterized in that rivet-like metal bolts (57) are pressed into thelaying channel (19).
 24. Process according to one of the precedingclaims, characterized in that use is made of a microcable or minicable(1) with a tube (8) consisting of chromium-nickel-molybdenum(CrNiMo188).
 25. Process according to one of claims 1 to 23,characterized in that use is made of a microcable or minicable with atube consisting of aluminium.
 26. Process according to one of claims 1to 23, characterized in that use is made of a microcable or minicablewith a tube (8) consisting of steel.
 27. Process according to one ofclaims 1 to 23, characterized in that use is made of a microcable orminicable with a tube (8) consisting of plastic.
 28. Process accordingto claim 27, characterized in that reinforcement elements, preferablyglass fibres, carbon fibres or a sintered carbon-fibre structure, areembedded in the plastic.
 29. Process according to one of the precedingclaims, characterized in that connecting sleeves and/or branchingsleeves (68) are arranged in the cable-laying route, and in that themicrocables or minicables (1) are guided in tightly through inlets andoutlets (70).
 30. Process according to claim 11, characterized in thatthe microcable or minicable (1) is provided with an expandable cablesheath.
 31. Process according to claim 11, characterized in that excesslengths of the microcable or minicable (1) in the form of U-shaped bendsare laid in the cable-laying route.
 32. Process according to one of thepreceding claims, characterized in that discharge means or feed means ofthe minicable or microcable (1) are run as an overhead cables or anon-supported cable.
 33. Process according to one of claims 1 to 23,characterized in that use is made of a microcable or minicable with atube (8) consisting of copper.
 34. Process according to one of thepreceding claims, characterized in that minishafts for receiving cablesleeves are arranged in the cable-laying route.
 35. Process according toone of the preceding claims, characterized in that the tubes (8) of theminicable or microcable (1) are provided with an inner coating offriction-reducing plastic, preferably PTFE.
 36. Process according toclaim 35, characterized in that the inner coating is separated out froman emulsion, preferably with the action of heat.
 37. Process accordingto one of the preceding claims, characterized in that, for theminicable, use is made of a tube with an internal diameter of more than1.8 mm.
 38. Process according to one of the preceding claims,characterized in that, for the minicable, use is made of a tube with awall thickness of from 0.2 to 0.4 mm.
 39. Process according to one ofthe preceding claims, characterized in that, for minicables, use is madeof tubes whose wall thickness to external diameter ratio is between ⅕ to{fraction (1/20)}, preferably {fraction (1/10)}.
 40. Process accordingto one of the preceding claims, characterized in that a laying channelis cut by means of a laying unit whose cutting-wheel arrangement isvaried in terms of thickness such that the width of the laying channelis adapted in one cutting operation to the corresponding diameter of themicrocable or minicable used.
 41. Process according to claim 40,characterized in that the cutting-wheel arrangement, comprising twoblades (TS1, TS2) and a spacer ring located therebetween, is drawn ontothe axle of the laying unit, the thickness of the the spacer ringdetermining the overall thickness of the cutting-wheel arrangement forthe necessary width of the laying channel.
 42. Process according to oneof claims 40 or 41, characterized in that use is made of a spacer ringwhich has circumferential cutouts or profiles, by way of which thelaying channel is simultaneously cleaned of cutting residues during thecutting operation.
 43. Process according to claim 42, characterized inthat the laying channel is cleaned by way of rectangular cutouts on thecircumference of the spacer ring.
 44. Process according to claim 42,characterized in that the laying channel is cleaned by way ofsawtooth-shaped cutouts on the circumference of the spacer ring. 45.Process according to claim 42, characterized in that the laying channelis cleaned by way of bar-like, flexible brushes (B) on the circumferenceof the spacer ring (DR).
 46. Laying unit for producing a laying channelfor receiving a minicable or microcable, characterized in that itcontains a cutting-wheel arrangement on whose drive axle (AS) there isarranged two blades (TS1, TS2) and, located therebetween, a spacer ring(DR) adapted to the necessary overall thickness.
 47. Laying unitaccording to claim 46, characterized in that the spacer ring (DR) hasrectangular cutouts (RA) on the circumference.
 48. Laying unit accordingto claim 46, characterized in that the spacer ring (DR) hassawtooth-shaped cutouts (SA) on the circumference.
 49. Laying unitaccording to claim 46, characterized in that the spacer ring (DR) hasbar-like, flexible brushes (B) on the circumference.
 50. Laying unitaccording to one of claims 46 to 49, characterized in that it is alsopossible for a material such as bitumen to be broken out by way of thecutouts of the blades TS1.
 51. Laying unit according to one of claims 46to 49, characterized in that the cutouts of the blades (TS) are providedwith hard-metal teeth (Z) which can be exchanged if required.
 52. Layingunit according to claim 51, characterized in that the hard-metal teeth(Z) are arranged in a staggered manner.
 53. Process according to one ofthe preceding claims, characterized in that a tension-resistant releaseelement (ZT, FP) for lifting the laid minicable or microcable (MK) isintroduced, when said cable is laid in the laying channel (VN), abovethe minicable or microcable (MK) in the filling material (FM) of thelaying channel (VN), in that the tension-resistant release element (ZT,FP) is then drawn out during the lifting operation, in which case thelaying channel (VN) is also released of filling material (FM), and inthat the minicable or microcable (MK) is then removed from the layingchannel (VN).
 54. Process according to claim 53, characterized in that aline (ZT) is laid as tension-resistant release element.
 55. Processaccording to claim 53, characterized in that a metal profile, preferablyconsisting of steel, is laid as tension-resistant release element (ZT).56. Process according to one of claims 53 or 55, characterized in thatthe tension-resistant release element (ZT) is laid in strip form. 57.Process according to claim 53, characterized in that the release element(ZT), initially adhering to the minicable or microcable (MK), is laid inone operation, and in that the release element (ZT) is ripped away fromthe minicable or microcable during the lifting operation, and in thatthe filling material (PM) is removed from the laying channel (VN)together with the ripped-away release element (ZT).
 58. Processaccording to claim 53, characterized in that the laying channel (VN) iscovered by a filling profile (FP), preferably consisting of rubber orplastic, which can be used as release means and is preferably introducedinto the laying channel (VN) with bitumen, in that, during the liftingoperation, the filling profile is first of all removed and the minicableor microcable (MK) is then lifted.
 59. Process according to one ofclaims 53 to 58, characterized in that a release means which preventswetting is introduced between the minicable or microcable (MK) in orderto keep as low as possible the adherence to the minicable or microcable(MK) of the filling material (FM) introduced into the laying channel.60. Process according to one of claims 53 to 57, characterized in thatthe tension-resistant release element (ZT) consisting of metal is usedfor the power supply along the route of the microcable.
 61. Processaccording to one of the preceding claims, characterized in that themetallic tubes of microcables or minicables (MK, MK1, MK2) are connectedto the central power supply.
 62. Process according to claim 61,characterized in that the electric through-connection between twomicrocables or minicables (MK1, MK2) is effected via a metallic cablesleeve (KM).
 63. Process according to one of claims 61 to 62,characterized in that the power is supplied via a minicable ormicrocable (MK) and an additionally laid power cable (SK, RL, ZS). 64.Process according to one of claims 61 to 63, characterized in that themicrocable or minicable (MK, MK1, MK2) is laid, without insulation, as areturn conductor.
 65. Process according to one of claims 61 to 63,characterized in that the minicable or microcable (MK) is provided withan insulation (IS) and is laid, with insulation, as a supply conductor,and a separate earth conductor is laid, without insulation, as a returnconductor (RL, NH).
 66. Process according to one of claims 61 to 65,characterized in that a cable holding-down device (NH) introduced in thelaying channel (VN) is used as current conductor.
 67. Process accordingto claim 61, characterized in that a minicable or microcable (MK) in acommon insulation (IS) is laid in the laying channel (VN) as powersupply conductor.
 68. Process according to claim 67, characterized inthat the insulated minicable or microcable (MK) and the insulatedadditional conductor (ZS) are connected to one another via a web (ST).69. Process according to claim 61, characterized in that two insulatedminicables or microcables (MK1, MK2) are introduced in the layingchannel (VN), the power being supplied via one cable and the power beingreturned via the second cable.
 70. Process according to claim 61,characterized in that two insulated minicables or microcables (MK1, MK2)are combined in an insulation (IS) and are introduced into the layingchannel (VN).
 71. Process according to one of the preceding claims,characterized in that the route of the optical minicable or microcable(MK) laid in a laying channel (VN) is followed with the aid of adetector (D).
 72. Process according to claim 71, characterized in that,as detector (D), use is made of the metal detector which is known perse.
 73. Process according to claim 71, characterized in that, asdetector (D), use is made of a georadar-like unit.
 74. Process accordingto claim 71, characterized in that, when the minicable or microcable(MK) is laid, magnets (M) whose magnetic fields are located with the aidof the detector (D) are introduced into the laying channel (VN). 75.Process according to claim 74, characterized in that the magnets (M) arearranged on individual, spaced-apart cable holding-down devices (NH).76. Process according to claim 74, characterized in that bar-like,magnetic cable holding-down devices (SNHM) are introduced, at distancesapart from one another, in the laying channel (VN).
 77. Processaccording to claim 76, characterized in that the bar-like magnetic cableholding-down devices (SNHM) are arranged on longitudinally runningsupport filaments (TF), such that they adhere to said filaments, and areintroduced into the laying channel (VN) as continuous, grid-like cableholding-down devices (GNH).
 78. Process according to claim 77,characterized in that the bar-like magnetic cable holding-down devices(SNHM) have their ends clamped onto the support filaments (TF). 79.Process according to claim 76, characterized in that the bar-likemagnetic cable holding-down devices (SNHM) have their ends (E) fittedinto a longitudinally running support sheet (TFOL).
 80. Processaccording to claim 74, characterized in that U-shaped, magnetic cableholding-down devices (NHM) are clamped into the laying channel (VN). 81.Process according to one of claims 74 to 80, characterized in that themagnets of the cable holding-down devices (M, SNHM, KNHM) are introducedwith alternate polarity (S, N) into the laying channel (VN), such that amagnetic coding is obtained for the laid minicable or microcable (MK),and that this coding for the laid minicable or microcable (MK) is thusevaluated with the aid of the detector (D).
 82. Process according toclaim 71, characterized in that the filling material of the layingchannel (VN) is provided with metallic fillers.
 83. Process according toclaim 71, characterized in that electronic components such as pulsegenerators (I) are installed in the cable holding-down devices (NH) foractive cable detection.
 84. Process according to claim 71, characterizedin that it is possible to connect to the microcable (MK) freelyprogrammable chips (C) which can give information on the condition andlaying of the microcables (MK) and may also be reprogrammedsubsequently.
 85. Process according to one of claims 71 to 84,characterized in that interrogation and programming are effected fromthe outside via induction loops (IS).
 86. Process according to claim 84,characterized in that the power supply and interrogation of the chips(C, CH) are effected from the sleeve (M).
 87. Process according to claim86, characterized in that the chip (CH) is accommodated in a sleeve (M)which is easily accessible and is controlled electrically from theoutside.
 88. Process according to claim 1, characterized in that, forsubsequently repairing a microcable with the aid of a unit (GF) forexposing the microcable (MK), the filling material (FM) is removed fromthe laying channel (VN) over a length which is required for theintroduction of a repair set, said repair set being formed from twocable sleeves (KM), two equalizing loops (AS) and a connecting tube (VR)between the cable sleeves (KM), in that the microcable (MK) is liftedout of the laying channel (FVN) freed of the filling material (FM), inthat the tube of the microcable (MK) is shortened over a length whichcorresponds to the repair set, and in that the repair set is connectedtightly to the two ends of the microcable (MK).
 89. Process according toclaim 88, characterized in that the filling material (FM) is removed bycutting taking place in the laying channel (VN).
 90. Process accordingto claim 88, characterized in that the filling material (FM) is removedwith the aid of a heatable cutter (SCH), by means of which the fillingmaterial (FM), preferably bitumen, is first of all heated and then cutout.
 91. Process according to one of claims 88 to 90, characterized inthat, tangentially to the exposed laying channel (FVN), two core holes(B) are drilled, at a distance from one another, vertically into theground (VG), in that a cable sleeve (KM) which is suitable for theconnection of microcables (MK) is introduced into each core hole (B), aconnecting tube (VR) which belongs to the repair set being introducedbetween the two cable sleeves (KM) in the exposed laying channel (FVN),and in that the ends of the microcable (MK) which is to be repaired areconnected tightly to tubular equalizing loops (AS) which are arranged atthe off cable-sleeve inlets (KE).
 92. Process according to claim 91,characterized in that the microcables (MK) are connected tightly to theequalizing loops (AS) by being crimped thereon (AK).
 93. Processaccording to one of claims 88 to 92, characterized in that use is madeof a measuring device (MV), preferably an electric continuity tester,which indicates that, upon exposure of the laying channel (VN), contactis made with the microcable (MK), and in that a lifting device (F) forthe cutting wheel or the cutter (SCH) is thus set in motion.
 94. Processaccording to claim 88, characterized in that the filling material (FM),at least the residue of the filling material (RFM), is removed from thelaying channel (VN) with the aid of a ripping wire laid along themicrocable (MK).
 95. Process according to one of claims 88 to 93,characterized in that the tube of a microcable (MK) is provided with abarely adhering insulation (IS), for example consisting of polyethylene,paper or a swelling nonwoven, which is slit open after the removal ofthe filling material (FM), with the result that the microcable (MK) canbe easily removed from the exposed laying channel (FVN) without adheringto the residual filling material (RFM).
 96. Process according to claim88, characterized in that the filling material (FM) is drawn out withthe aid of cable holding-down devices which run along above themicrocable (MK) in the laying channel (VN) and may be heated strongly ascurrent-carrying conductors.
 97. Process according to one of claims 88to 96, characterized in that the filling material (FM) is removed inlayers.
 98. Process according to one of claims 88 to 97, characterizedin that the filling material (FM) is removed from laying channels whichrun between individual slabs of a concrete roadway.
 99. Processaccording to one of claims 88 to 97, characterized in that the fillingmaterial (FM) is removed from laying channels which are arranged asexpansion joints in concrete slabs of a roadway, in which case, attransitions from one concrete slab to the other, the microcable runs incore holes which are likewise filled with filling material.
 100. Processaccording to one of claims 88 to 99, characterized in that the cablesheath is thickened or the microcable has applied over it a foam-rubberelement (GU) which is laid continuously in the longitudinal direction,protects the cable against mechanical damage and forms a release meansbetween the cable and bitumen.
 101. Process according to one of thepreceding claims, characterized in that the microcable (MK) is fixed ina laying channel (VN) in the ground (VG) with the aid of a continuousprofile body (GU, GUR, VP, NFT) consisting of elastic material, and inthat the laying channel (VG) is sealed by introducing a sealant (B,BVP).
 102. Process according to claim 101, characterized in that bitumenis used as the sealant (B, BVP).
 103. Process according to claim 101,characterized in that a hot-melt adhesive, preferably consisting ofpolyamide, is used as the sealant (B, BVP).
 104. Process according toone of claims 101 to 103, characterized in that use is made of a profilebody (GU) with circular cross-section.
 105. Process according to one ofclaims 101 to 103, characterized in that use is made of a profile body(GUR) with annular cross-section.
 106. Process according to one ofclaims 101 to 105, characterized in that use is made of a profile body(VP) which is adapted to the laying channel (VN) and has alongitudinally running duct for microcables (MK).
 107. Process accordingto claim 106, characterized in that use is made of a profile body (VP)with a plurality of free ducts (FK) running in parallel.
 108. Processaccording to claim 106 or 107, characterized in that optical waveguidesare introduced into the free ducts (FK).
 109. Process according to oneof claims 101 to 108, characterized in that use is made of a profilebody (VP) with barbs (WH) integrally formed laterally thereon. 110.Process according to one of claims 101 to 109, characterized in that, asthe profile body, use is made of a grooved moulding (NFT) whichcomprises an elastic profile (P) which is coated with sealant (BVP) andhas free ducts (FK).
 111. Process according to one of claims 101 to 110,characterized. in that the sealant (B, BVP) is softened by the supply ofheat, in particular by infrared radiation (IS), before being pressedinto the laying channel (VN).
 112. Process according to one of claims101 to 111, characterized in that the laying of the microcable (MK)followed by the laying of the profile body (GU, GUR, NFT) in the layingchannel (VN) and the sealing of the laying channel (VN) by means of asealant (B, BVP) are effected with the aid of a combined laying machine(VW), which carries along a drum for microcable (TMK) and a drum forprofile body (TGU).
 113. Process according to one of claims 101 to 112,characterized in that an additional profile (ZP) is introduced on aprofile body (GU, GUR, VP, NFT) which has already been introduced. 114.Process according to one of the preceding claims, characterized in that,after, or simultaneously with, the introduction of the minicable ormicrocable (MK) into a laying channel (VN), an elastic,notch-impact-resistant covering profile (AP) which is difficult to cutthrough from the outside by mechanical intervention is laid in thelongitudinal direction of the minicable or microcable (MK), and in thatthe width of the laying channel (VN) is covered in so doing. 115.Process according to claim 114, characterized in that a covering profile(AP) comprising a metal wire or a plastic, hemp or sisal line is laid inthe laying channel (VN).
 116. Process according to claim 114,characterized in that a covering profile (AP) with a core (MFK) which isdifficult to cut through mechanically and an elastic sheathing (APU)consisting of plastic material, preferably of foam, is introduced, thecore (MFK) comprising one or more metal wires or one or more plastic,hemp or sisal filaments.
 117. Process according to claim 116,characterized in that use is made of a covering profile (AP) in whichthe core (MFK) is formed by stranded filaments.
 118. Process accordingto one of the preceding claims, characterized in that an intermediatecovering (ZWA) is introduced between the minicable or microcable (MK)and the covering profile (AP).
 119. Process according to claim 118,characterized in that use is made of an intermediate covering (ZWA) withinserts (ZWE), preferably comprising metallic wires.
 120. Processaccording to one of claims 118 or 119, characterized in that use is madeof an intermediate covering (ZWA) with sensors introduced therein. 121.Process according to one of the preceding claims, characterized in thatuse is made of a minicable or microcable (MK) with a tube (MKR)consisting of plastic.
 122. Process according to one of the precedingclaims, characterized in that electrically conductive metal lines (ZWE)are arranged in the covering profile (AP) or in the intermediatecovering (ZWA) for locating the cable-laying route.